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  • Anatomy of a .NET Assembly - Custom attribute encoding

    - by Simon Cooper
    In my previous post, I covered how field, method, and other types of signatures are encoded in a .NET assembly. Custom attribute signatures differ quite a bit from these, which consequently affects attribute specifications in C#. Custom attribute specifications In C#, you can apply a custom attribute to a type or type member, specifying a constructor as well as the values of fields or properties on the attribute type: public class ExampleAttribute : Attribute { public ExampleAttribute(int ctorArg1, string ctorArg2) { ... } public Type ExampleType { get; set; } } [Example(5, "6", ExampleType = typeof(string))] public class C { ... } How does this specification actually get encoded and stored in an assembly? Specification blob values Custom attribute specification signatures use the same building blocks as other types of signatures; the ELEMENT_TYPE structure. However, they significantly differ from other types of signatures, in that the actual parameter values need to be stored along with type information. There are two types of specification arguments in a signature blob; fixed args and named args. Fixed args are the arguments to the attribute type constructor, named arguments are specified after the constructor arguments to provide a value to a field or property on the constructed attribute type (PropertyName = propValue) Values in an attribute blob are limited to one of the basic types (one of the number types, character, or boolean), a reference to a type, an enum (which, in .NET, has to use one of the integer types as a base representation), or arrays of any of those. Enums and the basic types are easy to store in a blob - you simply store the binary representation. Strings are stored starting with a compressed integer indicating the length of the string, followed by the UTF8 characters. Array values start with an integer indicating the number of elements in the array, then the item values concatentated together. Rather than using a coded token, Type values are stored using a string representing the type name and fully qualified assembly name (for example, MyNs.MyType, MyAssembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=0123456789abcdef). If the type is in the current assembly or mscorlib then just the type name can be used. This is probably done to prevent direct references between assemblies solely because of attribute specification arguments; assemblies can be loaded in the reflection-only context and attribute arguments still processed, without loading the entire assembly. Fixed and named arguments Each entry in the CustomAttribute metadata table contains a reference to the object the attribute is applied to, the attribute constructor, and the specification blob. The number and type of arguments to the constructor (the fixed args) can be worked out by the method signature referenced by the attribute constructor, and so the fixed args can simply be concatenated together in the blob without any extra type information. Named args are different. These specify the value to assign to a field or property once the attribute type has been constructed. In the CLR, fields and properties can be overloaded just on their type; different fields and properties can have the same name. Therefore, to uniquely identify a field or property you need: Whether it's a field or property (indicated using byte values 0x53 and 0x54, respectively) The field or property type The field or property name After the fixed arg values is a 2-byte number specifying the number of named args in the blob. Each named argument has the above information concatenated together, mostly using the basic ELEMENT_TYPE values, in the same way as a method or field signature. A Type argument is represented using the byte 0x50, and an enum argument is represented using the byte 0x55 followed by a string specifying the name and assembly of the enum type. The named argument property information is followed by the argument value, using the same encoding as fixed args. Boxed objects This would be all very well, were it not for object and object[]. Arguments and properties of type object allow a value of any allowed argument type to be specified. As a result, more information needs to be specified in the blob to interpret the argument bytes as the correct type. So, the argument value is simple prepended with the type of the value by specifying the ELEMENT_TYPE or name of the enum the value represents. For named arguments, a field or property of type object is represented using the byte 0x51, with the actual type specified in the argument value. Some examples... All property signatures start with the 2-byte value 0x0001. Similar to my previous post in the series, names in capitals correspond to a particular byte value in the ELEMENT_TYPE structure. For strings, I'll simply give the string value, rather than the length and UTF8 encoding in the actual blob. I'll be using the following enum and attribute types to demonstrate specification encodings: class AttrAttribute : Attribute { public AttrAttribute() {} public AttrAttribute(Type[] tArray) {} public AttrAttribute(object o) {} public AttrAttribute(MyEnum e) {} public AttrAttribute(ushort x, int y) {} public AttrAttribute(string str, Type type1, Type type2) {} public int Prop1 { get; set; } public object Prop2 { get; set; } public object[] ObjectArray; } enum MyEnum : int { Val1 = 1, Val2 = 2 } Now, some examples: Here, the the specification binds to the (ushort, int) attribute constructor, with fixed args only. The specification blob starts off with a prolog, followed by the two constructor arguments, then the number of named arguments (zero): [Attr(42, 84)] 0x0001 0x002a 0x00000054 0x0000 An example of string and type encoding: [Attr("MyString", typeof(Array), typeof(System.Windows.Forms.Form))] 0x0001 "MyString" "System.Array" "System.Windows.Forms.Form, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" 0x0000 As you can see, the full assembly specification of a type is only needed if the type isn't in the current assembly or mscorlib. Note, however, that the C# compiler currently chooses to fully-qualify mscorlib types anyway. An object argument (this binds to the object attribute constructor), and two named arguments (a null string is represented by 0xff and the empty string by 0x00) [Attr((ushort)40, Prop1 = 12, Prop2 = "")] 0x0001 U2 0x0028 0x0002 0x54 I4 "Prop1" 0x0000000c 0x54 0x51 "Prop2" STRING 0x00 Right, more complicated now. A type array as a fixed argument: [Attr(new[] { typeof(string), typeof(object) })] 0x0001 0x00000002 // the number of elements "System.String" "System.Object" 0x0000 An enum value, which is simply represented using the underlying value. The CLR works out that it's an enum using information in the attribute constructor signature: [Attr(MyEnum.Val1)] 0x0001 0x00000001 0x0000 And finally, a null array, and an object array as a named argument: [Attr((Type[])null, ObjectArray = new object[] { (byte)2, typeof(decimal), null, MyEnum.Val2 })] 0x0001 0xffffffff 0x0001 0x53 SZARRAY 0x51 "ObjectArray" 0x00000004 U1 0x02 0x50 "System.Decimal" STRING 0xff 0x55 "MyEnum" 0x00000002 As you'll notice, a null object is encoded as a null string value, and a null array is represented using a length of -1 (0xffffffff). How does this affect C#? So, we can now explain why the limits on attribute arguments are so strict in C#. Attribute specification blobs are limited to basic numbers, enums, types, and arrays. As you can see, this is because the raw CLR encoding can only accommodate those types. Special byte patterns have to be used to indicate object, string, Type, or enum values in named arguments; you can't specify an arbitary object type, as there isn't a generalised way of encoding the resulting value in the specification blob. In particular, decimal values can't be encoded, as it isn't a 'built-in' CLR type that has a native representation (you'll notice that decimal constants in C# programs are compiled as several integer arguments to DecimalConstantAttribute). Jagged arrays also aren't natively supported, although you can get around it by using an array as a value to an object argument: [Attr(new object[] { new object[] { new Type[] { typeof(string) } }, 42 })] Finally... Phew! That was a bit longer than I thought it would be. Custom attribute encodings are complicated! Hopefully this series has been an informative look at what exactly goes on inside a .NET assembly. In the next blog posts, I'll be carrying on with the 'Inside Red Gate' series.

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  • ASP.NET WebAPI Security 3: Extensible Authentication Framework

    - by Your DisplayName here!
    In my last post, I described the identity architecture of ASP.NET Web API. The short version was, that Web API (beta 1) does not really have an authentication system on its own, but inherits the client security context from its host. This is fine in many situations (e.g. AJAX style callbacks with an already established logon session). But there are many cases where you don’t use the containing web application for authentication, but need to do it yourself. Examples of that would be token based authentication and clients that don’t run in the context of the web application (e.g. desktop clients / mobile). Since Web API provides a nice extensibility model, it is easy to implement whatever security framework you want on top of it. My design goals were: Easy to use. Extensible. Claims-based. ..and of course, this should always behave the same, regardless of the hosting environment. In the rest of the post I am outlining some of the bits and pieces, So you know what you are dealing with, in case you want to try the code. At the very heart… is a so called message handler. This is a Web API extensibility point that gets to see (and modify if needed) all incoming and outgoing requests. Handlers run after the conversion from host to Web API, which means that handler code deals with HttpRequestMessage and HttpResponseMessage. See Pedro’s post for more information on the processing pipeline. This handler requires a configuration object for initialization. Currently this is very simple, it contains: Settings for the various authentication and credential types Settings for claims transformation Ability to block identity inheritance from host The most important part here is the credential type support, but I will come back to that later. The logic of the message handler is simple: Look at the incoming request. If the request contains an authorization header, try to authenticate the client. If this is successful, create a claims principal and populate the usual places. If not, return a 401 status code and set the Www-Authenticate header. Look at outgoing response, if the status code is 401, set the Www-Authenticate header. Credential type support Under the covers I use the WIF security token handler infrastructure to validate credentials and to turn security tokens into claims. The idea is simple: an authorization header consists of two pieces: the schema and the actual “token”. My configuration object allows to associate a security token handler with a scheme. This way you only need to implement support for a specific credential type, and map that to the incoming scheme value. The current version supports HTTP Basic Authentication as well as SAML and SWT tokens. (I needed to do some surgery on the standard security token handlers, since WIF does not directly support string-ified tokens. The next version of .NET will fix that, and the code should become simpler then). You can e.g. use this code to hook up a username/password handler to the Basic scheme (the default scheme name for Basic Authentication). config.Handler.AddBasicAuthenticationHandler( (username, password) => username == password); You simply have to provide a password validation function which could of course point back to your existing password library or e.g. membership. The following code maps a token handler for Simple Web Tokens (SWT) to the Bearer scheme (the currently favoured scheme name for OAuth2). You simply have to specify the issuer name, realm and shared signature key: config.Handler.AddSimpleWebTokenHandler(     "Bearer",     http://identity.thinktecture.com/trust,     Constants.Realm,     "Dc9Mpi3jaaaUpBQpa/4R7XtUsa3D/ALSjTVvK8IUZbg="); For certain integration scenarios it is very useful if your Web API can consume SAML tokens. This is also easily accomplishable. The following code uses the standard WIF API to configure the usual SAMLisms like issuer, audience, service certificate and certificate validation. Both SAML 1.1 and 2.0 are supported. var registry = new ConfigurationBasedIssuerNameRegistry(); registry.AddTrustedIssuer( "d1 c5 b1 25 97 d0 36 94 65 1c e2 64 fe 48 06 01 35 f7 bd db", "ADFS"); var adfsConfig = new SecurityTokenHandlerConfiguration(); adfsConfig.AudienceRestriction.AllowedAudienceUris.Add( new Uri(Constants.Realm)); adfsConfig.IssuerNameRegistry = registry; adfsConfig.CertificateValidator = X509CertificateValidator.None; // token decryption (read from configuration section) adfsConfig.ServiceTokenResolver = FederatedAuthentication.ServiceConfiguration.CreateAggregateTokenResolver(); config.Handler.AddSaml11SecurityTokenHandler("SAML", adfsConfig); Claims Transformation After successful authentication, if configured, the standard WIF ClaimsAuthenticationManager is called to run claims transformation and validation logic. This stage is used to transform the “technical” claims from the security token into application claims. You can either have a separate transformation logic, or share on e.g. with the containing web application. That’s just a matter of configuration. Adding the authentication handler to a Web API application In the spirit of Web API this is done in code, e.g. global.asax for web hosting: protected void Application_Start() {     AreaRegistration.RegisterAllAreas();     ConfigureApis(GlobalConfiguration.Configuration);     RegisterGlobalFilters(GlobalFilters.Filters);     RegisterRoutes(RouteTable.Routes);     BundleTable.Bundles.RegisterTemplateBundles(); } private void ConfigureApis(HttpConfiguration configuration) {     configuration.MessageHandlers.Add( new AuthenticationHandler(ConfigureAuthentication())); } private AuthenticationConfiguration ConfigureAuthentication() {     var config = new AuthenticationConfiguration     {         // sample claims transformation for consultants sample, comment out to see raw claims         ClaimsAuthenticationManager = new ApiClaimsTransformer(),         // value of the www-authenticate header, // if not set, the first scheme added to the handler collection is used         DefaultAuthenticationScheme = "Basic"     };     // add token handlers - see above     return config; } You can find the full source code and some samples here. In the next post I will describe some of the samples in the download, and then move on to authorization. HTH

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  • Advice for a distracted, unhappy, recently graduated programmer? [closed]

    - by Re-Invent
    I graduated 4 months ago. I had offers from a few good places to work at. At the same time I wanted to stick to building a small software business of my own, still have some ideas with good potential, some half done projects frozen in my github. But due to social pressures, I chose a job, the pay is great, but I am half-passionate about it. A small team of smart folks building useful product, working out contracts across the world. I've started finding it extremely boring. Boring to the extent that I skip 2-3 days a week together not doing work. Neither do I spend that time progressing any of my own projects. Yes, I feel stupid at the way I'm wasting time, but I don't understand exactly why is it happening. It's as if all the excitement has been drained. What can I do about it? Long version: School - I was in third standard. Only students, 6th grade had access to computer labs. I once peeked into the lab from the little door opening. No hard-disks, MS DOS on 5 1/2 inch floppies. I asked a senior student to play some sound in BASIC. He used PLAY to compose a tune. Boy! I was so excited, I was jumping from within. Back home, asked my brother to teach me some programming. We bought a book "MODERN All About GW-BASIC for Schools & Colleges". The book had everything, right from printing, to taking input, file i/o, game programming, machine level support, etc. I was in 6th standard, wrote my first game - a wheel of fortune, rotated the wheel by manipulating 16 color palette's definition. Got internet soon, got hooked to QuickBasic programming community. Made some more games "007 in Danger", "Car Crush 2" for submission to allbasiccode archives. I was extremely excited about all this. My interests now swayed into "hacking" (computer security). Taught myself some perl, found it annoying, learnt PHP and a bit of SQL. Also taught myself Visual Basic one of the winters and wrote a pacman clone with Direct X. By the time I was in 10th standard, I created some evil tools using visual basic, php and mysql and eventually landed myself into an unpaid side-job at a government facility, building evil tools for them. It was a dream come true for crackers of that time. And so was I, still very excited. Things changed soon, last two years of school were not so great as I was balancing preps for college, work at govt. and studies for school at same time. College - College was opposite of all I had wished it to be. I imagined it to be a place where I'd spend my 4 years building something awesome. It was rather an epitome of rote learning, attendance, rules, busy schedules, ban on personal laptops, hardly any hackers surrounding you and shit like that. We had to take permissions to even introduce some cultural/creative activities in our annual schedule. The labs won't be open on weekends because the lab employees had to have their leaves. Yes, a horrible place for someone like me. I still managed to pull out a project with a friend over 2 months. Showed it to people high in the academia hierarchy. They were immensely impressed, we proposed to allow personal computers for students. They made up half-assed reasons and didn't agree. We felt frustrated. And so on, I still managed to teach myself new languages, do new projects of my own, do an intern at the same govt. facility, start a small business for sometime, give a talk at a conference I'm passionate about, win game-dev and hacking contest at most respected colleges, solve good deal of programming contest problems, etc. At the same time I was not content with all these restrictions, great emphasis on rote learning, and sheer wastage of time due to college. I never felt I was overdoing, but now I feel I burnt myself out. During my last days at college, I did an intern at a bigco. While I spent my time building prototypes for certain LBS, the other interns around me, even a good friend, was just skipping time. I thought maybe, in a few weeks he would put in some serious efforts at work assigned to him, but all he did was to find creative ways to skip work, hide his face from manager, engage people in talks if they try to question his progress, etc. I tried a few time to get him on track, but it seems all he wanted was to "not to work hard at all and still reap the fruits". I don't know how others take such people, but I find their vicinity very very poisonous to one's own motivation and productivity. Over that, the place where I come from, HRs don't give much value to what have you done past 4 years. So towards the end of out intern, we all were offered work at the bigco, but the slacker, even after not writing more than 200 lines of code was made a much better offer. I felt enraged instantly - "Is this how the corp world treats someone who does fruitful, if not extra-ordinary work form them for past 6 months?". Yes, I did try to negotiate and debate. The bigcos seem blind due to departmentalization of responsibilities and many layers of management. I decided not to be in touch with any characters of that depressing play. Probably the busy time I had at college, ignoring friends, ignoring fun and squeezing every bit of free time for myself is also responsible. Probably this is what has drained all my willingness to work for anyone. I find my day job boring, at the same time I with to maintain it for financial reasons. I feel a bit burnt out, unsatisfied and at the same time an urge to quit working for someone else and start finishing my frozen side-projects (which may be profitable). Though I haven't got much to support myself with food, office, internet bills, etc in savings. I still have my day job, but I don't find it very interesting, even though the pay is higher than the slacker, I don't find money to be a great motivator here. I keep comparing myself to my past version. I wonder how to get rid of this and reboot myself back to the way I was in school days - excited about it, tinkering, building, learning new things daily, and NOT BORED?

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  • Oracle Support Master Note for Troubleshooting Advanced Queuing and Oracle Streams Propagation Issues (Doc ID 233099.1)

    - by faye.todd(at)oracle.com
    Master Note for Troubleshooting Advanced Queuing and Oracle Streams Propagation Issues (Doc ID 233099.1) Copyright (c) 2010, Oracle Corporation. All Rights Reserved. In this Document  Purpose  Last Review Date  Instructions for the Reader  Troubleshooting Details     1. Scope and Application      2. Definitions and Classifications     3. How to Use This Guide     4. Basic AQ Propagation Troubleshooting     5. Additional Troubleshooting Steps for AQ Propagation of User-Enqueued and Dequeued Messages     6. Additional Troubleshooting Steps for Propagation in an Oracle Streams Environment     7. Performance Issues  References Applies to: Oracle Server - Enterprise Edition - Version: 8.1.7.0 to 11.2.0.2 - Release: 8.1.7 to 11.2Information in this document applies to any platform. Purpose This document presents a step-by-step methodology for troubleshooting and resolving problems with Advanced Queuing Propagation in both Streams and basic Advanced Queuing environments. It also serves as a master reference for other more specific notes on Oracle Streams Propagation and Advanced Queuing Propagation issues. Last Review Date December 20, 2010 Instructions for the Reader A Troubleshooting Guide is provided to assist in debugging a specific issue. When possible, diagnostic tools are included in the document to assist in troubleshooting. Troubleshooting Details 1. Scope and Application This note is intended for Database Administrators of Oracle databases where issues are being encountered with propagating messages between advanced queues, whether the queues are used for user-created messaging systems or for Oracle Streams. It contains troubleshooting steps and links to notes for further problem resolution.It can also be used a template to document a problem when it is necessary to engage Oracle Support Services. Knowing what is NOT happening can frequently speed up the resolution process by focusing solely on the pertinent problem area. This guide is divided into five parts: Section 2: Definitions and Classifications (discusses the different types and features of propagations possible - helpful for understanding the rest of the guide) Section 3: How to Use this Guide (to be used as a start part for determining the scope of the problem and what sections to consult) Section 4. Basic AQ propagation troubleshooting (applies to both AQ propagation of user enqueued and dequeued messages as well as Oracle Streams propagations) Section 5. Additional troubleshooting steps for AQ propagation of user enqueued and dequeued messages Section 6. Additional troubleshooting steps for Oracle Streams propagation Section 7. Performance issues 2. Definitions and Classifications Given the potential scope of issues that can be encountered with AQ propagation, the first recommended step is to do some basic diagnosis to determine the type of problem that is being encountered. 2.1. What Type of Propagation is Being Used? 2.1.1. Buffered Messaging For an advanced queue, messages can be maintained on disk (persistent messaging) or in memory (buffered messaging). To determine if a queue is buffered or not, reference the GV_$BUFFERED_QUEUES view. If the queue does not appear in this view, it is persistent. 2.1.2. Propagation mode - queue-to-dblink vs queue-to-queue As of 10.2, an AQ propagation can also be defined as queue-to-dblink, or queue-to-queue: queue-to-dblink: The propagation delivers messages or events from the source queue to all subscribing queues at the destination database identified by the dblink. A single propagation schedule is used to propagate messages to all subscribing queues. Hence any changes made to this schedule will affect message delivery to all the subscribing queues. This mode does not support multiple propagations from the same source queue to the same target database. queue-to-queue: Added in 10.2, this propagation mode delivers messages or events from the source queue to a specific destination queue identified on the database link. This allows the user to have fine-grained control on the propagation schedule for message delivery. This new propagation mode also supports transparent failover when propagating to a destination Oracle RAC system. With queue-to-queue propagation, you are no longer required to re-point a database link if the owner instance of the queue fails on Oracle RAC. This mode supports multiple propagations to the same target database if the target queues are different. The default is queue-to-dblink. To verify if queue-to-queue propagation is being used, in non-Streams environments query DBA_QUEUE_SCHEDULES.DESTINATION - if a remote queue is listed along with the remote database link, then queue-to-queue propagation is being used. For Streams environments, the DBA_PROPAGATION.QUEUE_TO_QUEUE column can be checked.See the following note for a method to switch between the two modes:Document 827473.1 How to alter propagation from queue-to-queue to queue-to-dblink 2.1.3. Combined Capture and Apply (CCA) for Streams In 11g Oracle Streams environments, an optimization called Combined Capture and Apply (CCA) is implemented by default when possible. Although a propagation is configured in this case, Streams does not use it; instead it passes information directly from capture to an apply receiver. To see if CCA is in use: COLUMN CAPTURE_NAME HEADING 'Capture Name' FORMAT A30COLUMN OPTIMIZATION HEADING 'CCA Mode?' FORMAT A10SELECT CAPTURE_NAME, DECODE(OPTIMIZATION,0, 'No','Yes') OPTIMIZATIONFROM V$STREAMS_CAPTURE; Also, see the following note:Document 463820.1 Streams Combined Capture and Apply in 11g 2.2. Queue Table Compatibility There are three types of queue table compatibility. In more recent databases, queue tables may be present in all three modes of compatibility: 8.0 - earliest version, deprecated in 10.2 onwards 8.1 - support added for RAC, asynchronous notification, secure queues, queue level access control, rule-based subscribers, separate storage of history information 10.0 - if the database is in 10.1-compatible mode, then the default value for queue table compatibility is 10.0 2.3. Single vs Multiple Consumer Queue Tables If more than one recipient can dequeue a message from a queue, then its queue table is multiple consumer. You can propagate messages from a multiple-consumer queue to a single-consumer queue. Propagation from a single-consumer queue to a multiple-consumer queue is not possible. 3. How to Use This Guide 3.1. Are Messages Being Propagated at All, or is the Propagation Just Slow? Run the following query on the source database for the propagation (assuming that it is running): select TOTAL_NUMBER from DBA_QUEUE_SCHEDULES where QNAME='<source_queue_name>'; If TOTAL_NUMBER is increasing, then propagation is most likely functioning, although it may be slow. For performance issues, see Section 7. 3.2. Propagation Between Persistent User-Created Queues See Sections 4 and 5 (and optionally Section 6 if performance is an issue). 3.3. Propagation Between Buffered User-Created Queues See Sections 4, 5, and 6 (and optionally Section 7 if performance is an issue). 3.4. Propagation between Oracle Streams Queues (without Combined Capture and Apply (CCA) Optimization) See Sections 4 and 6 (and optionally Section 7 if performance is an issue). 3.5. Propagation between Oracle Streams Queues (with Combined Capture and Apply (CCA) Optimization) Although an AQ propagation is not used directly in this case, some characteristics of the message transfer are inferred from the propagation parameters used. Some parts of Sections 4 and 6 still apply. 3.6. Messaging Gateway Propagations This note does not apply to Messaging Gateway propagations. 4. Basic AQ Propagation Troubleshooting 4.1. Double-check Your Code Make sure that you are consistent in your usage of the database link(s) names, queue names, etc. It may be useful to plot a diagram of which queues are connected via which database links to make sure that the logical structure is correct. 4.2. Verify that Job Queue Processes are Running 4.2.1. Versions 10.2 and Lower - DBA_JOBS Package For versions 10.2 and lower, a scheduled propagation is managed by DBMS_JOB package. The propagation is performed by job queue process background processes. Therefore we need to verify that there are sufficient processes available for the propagation process. We should have at least 4 job queue processes running and preferably more depending on the number of other jobs running in the database. It should be noted that for AQ specific work, AQ will only ever use half of the job queue processes available.An issue caused by an inadequate job queue processes parameter setting is described in the following note:Document 298015.1 Kwqjswproc:Excep After Loop: Assigning To Self 4.2.1.1. Job Queue Processes in Initalization Parameter File The parameter JOB_QUEUE_PROCESSES in the init.ora/spfile should be > 0. The value can be changed dynamically via connect / as sysdbaalter system set JOB_QUEUE_PROCESSES=10; 4.2.1.2. Job Queue Processes in Memory The following command will show how many job queue processes are currentlyin use by this instance (this may be different than what is in the init.ora/spfile): connect / as sysdbashow parameter job; 4.2.1.3. OS PIDs Corresponding to Job Queue Processes Identify the operating system process ids (spids) of job queue processes involved in propagation via select p.SPID, p.PROGRAM from V$PROCESS p, DBA_JOBS_RUNNING jr, V$SESSION s, DBA_JOBS j where s.SID=jr.SID and s.PADDR=p.ADDR and jr.JOB=j.JOBand j.WHAT like '%sys.dbms_aqadm.aq$_propaq(job)%'; and these SPIDs can be used to check at the operating system level that they exist.In 8i a job queue process will have a name similar to: ora_snp1_<instance_name>.In 9i onwards you will see a coordinator process: ora_cjq0_ and multiple slave processes: ora_jnnn_<instance_name>, where nnn is an integer between 1 and 999. 4.2.2. Version 11.1 and Above - Oracle Scheduler In version 11.1 and above, Oracle Scheduler is used to perform AQ and Streams propagations. Oracle Scheduler automatically tunes the number of slave processes for these jobs based on the load on the computer system, and the JOB_QUEUE_PROCESSES initialization parameter is only used to specify the maximum number of slave processes. Therefore, the JOB_QUEUE_PROCESSES initialization parameter does not need to be set (it defaults to a very high number), unless you want to limit the number of slaves that can be created. If JOB_QUEUE_PROCESSES = 0, no propagation jobs will run.See the following note for a discussion of Oracle Streams 11g and Oracle Scheduler:Document 1083608.1 11g Streams and Oracle Scheduler 4.2.2.1. Job Queue Processes in Initalization Parameter File The parameter JOB_QUEUE_PROCESSES in the init.ora/spfile should be > 0, and preferably be left at its default value. The value can be changed dynamically via connect / as sysdbaalter system set JOB_QUEUE_PROCESSES=10; To set the JOB_QUEUE_PROCESSES parameter to its default value, run: connect / as sysdbaalter system reset JOB_QUEUE_PROCESSES; and then bounce the instance. 4.2.2.2. Job Queue Processes in Memory The following command will show how many job queue processes are currently in use by this instance (this may be different than what is in the init.ora/spfile): connect / as sysdbashow parameter job; 4.2.2.3. OS PIDs Corresponding to Job Queue Processes Identify the operating system process ids (SPIDs) of job queue processes involved in propagation via col PROGRAM for a30select p.SPID, p.PROGRAM, j.JOB_namefrom v$PROCESS p, DBA_SCHEDULER_RUNNING_JOBS jr, V$SESSION s, DBA_SCHEDULER_JOBS j where s.SID=jr.SESSION_ID and s.PADDR=p.ADDRand jr.JOB_name=j.JOB_NAME and j.JOB_NAME like '%AQ_JOB$_%'; and these SPIDs can be used to check at the operating system level that they exist.You will see a coordinator process: ora_cjq0_ and multiple slave processes: ora_jnnn_<instance_name>, where nnn is an integer between 1 and 999. 4.3. Check the Alert Log and Any Associated Trace Files The first place to check for propagation failures is the alert logs at all sites (local and if relevant all remote sites). When a job queue process attempts to execute a schedule and fails it will always write an error stack to the alert log. This error stack will also be written in a job queue process trace file, which will be written to the BACKGROUND_DUMP_DEST location for 10.2 and below, and in the DIAGNOSTIC_DEST location for 11g. The fact that errors are written to the alert log demonstrates that the schedule is executing. This means that the problem could be with the set up of the schedule. In this example the ORA-02068 demonstrates that the failure was at the remote site. Further investigation revealed that the remote database was not open, hence the ORA-03114 error. Starting the database resolved the problem. Thu Feb 14 10:40:05 2002 Propagation Schedule for (AQADM.MULTIPLEQ, SHANE816.WORLD) encountered following error:ORA-04052: error occurred when looking up Remote object [email protected]: error occurred at recursive SQL level 4ORA-02068: following severe error from SHANE816ORA-03114: not connected to ORACLEORA-06512: at "SYS.DBMS_AQADM_SYS", line 4770ORA-06512: at "SYS.DBMS_AQADM", line 548ORA-06512: at line 1 Other potential errors that may be written to the alert log can be found in the following notes:Document 827184.1 AQ Propagation with CLOB data types Fails with ORA-22990 (11.1)Document 846297.1 AQ Propagation Fails : ORA-00600[kope2upic2954] or Ora-00600[Kghsstream_copyn] (10.2, 11.1)Document 731292.1 ORA-25215 Reported on Local Propagation When Using Transformation with ANYDATA queue tables (10.2, 11.1, 11.2)Document 365093.1 ORA-07445 [kwqppay2aqe()+7360] Reported on Propagation of a Transformed Message (10.1, 10.2)Document 219416.1 Advanced Queuing Propagation Fails with ORA-22922 (9.0)Document 1203544.1 AQ Propagation Aborted with ORA-600 [ociksin: invalid status] on SYS.DBMS_AQADM_SYS.AQ$_PROPAGATION_PROCEDURE After Upgrade (11.1, 11.2)Document 1087324.1 ORA-01405 ORA-01422 reported by Advanced Queuing Propagation schedules after RAC reconfiguration (10.2)Document 1079577.1 Advanced Queuing Propagation Fails With "ORA-22370 incorrect usage of method" (9.2, 10.2, 11.1, 11.2)Document 332792.1 ORA-04061 error relating to SYS.DBMS_PRVTAQIP reported when setting up Statspack (8.1, 9.0, 9.2, 10.1)Document 353325.1 ORA-24056: Internal inconsistency for QUEUE <queue_name> and destination <dblink> (8.1, 9.0, 9.2, 10.1, 10.2, 11.1, 11.2)Document 787367.1 ORA-22275 reported on Propagating Messages with LOB component when propagating between 10.1 and 10.2 (10.1, 10.2)Document 566622.1 ORA-22275 when propagating >4K AQ$_JMS_TEXT_MESSAGEs from 9.2.0.8 to 10.2.0.1 (9.2, 10.1)Document 731539.1 ORA-29268: HTTP client error 401 Unauthorized Error when the AQ Servlet attempts to Propagate a message via HTTP (9.0, 9.2, 10.1, 10.2, 11.1)Document 253131.1 Concurrent Writes May Corrupt LOB Segment When Using Auto Segment Space Management (ORA-1555) (9.2)Document 118884.1 How to unschedule a propagation schedule stuck in pending stateDocument 222992.1 DBMS_AQADM.DISABLE_PROPAGATION_SCHEDULE Returns ORA-24082Document 282987.1 Propagated Messages marked UNDELIVERABLE after Drop and Recreate Of Remote QueueDocument 1204080.1 AQ Propagation Failing With ORA-25329 After Upgraded From 8i or 9i to 10g or 11g.Document 1233675.1 AQ Propagation stops after upgrade to 11.2.0.1 ORA-30757 4.3.1. Errors Related to Incorrect Network Configuration The most common propagation errors result from an incorrect network configuration. The list below contains common errors caused by tnsnames.ora file or database links being configured incorrectly: - ORA-12154: TNS:could not resolve service name- ORA-12505: TNS:listener does not currently know of SID given in connect descriptor- ORA-12514: TNS:listener could not resolve SERVICE_NAME - ORA-12541: TNS-12541 TNS:no listener 4.4. Check the Database Links Exist and are Functioning Correctly For schedules to remote databases confirm the database link exists via. SQL> col DBLINK for a45SQL> select QNAME, NVL(REGEXP_SUBSTR(DESTINATION, '[^@]+', 1, 2), DESTINATION) dblink2 from DBA_QUEUE_SCHEDULES3 where MESSAGE_DELIVERY_MODE = 'PERSISTENT';QNAME DBLINK------------------------------ ---------------------------------------------MY_QUEUE ORCL102B.WORLD Connect as the owner of the link and select across it to verify it works and connects to the database we expect. i.e. select * from ALL_QUEUES@ ORCL102B.WORLD; You need to ensure that the userid that scheduled the propagation (using DBMS_AQADM.SCHEDULE_PROPAGATION or DBMS_PROPAGATION_ADM.CREATE_PROPAGATION if using Streams) has access to the database link for the destination. 4.5. Has Propagation Been Correctly Scheduled? Check that the propagation schedule has been created and that a job queue process has been assigned. Look for the entry in DBA_QUEUE_SCHEDULES and SYS.AQ$_SCHEDULES for your schedule. For 10g and below, check that it has a JOBNO entry in SYS.AQ$_SCHEDULES, and that there is an entry in DBA_JOBS with that JOBNO. For 11g and above, check that the schedule has a JOB_NAME entry in SYS.AQ$_SCHEDULES, and that there is an entry in DBA_SCHEDULER_JOBS with that JOB_NAME. Check the destination is as intended and spelled correctly. SQL> select SCHEMA, QNAME, DESTINATION, SCHEDULE_DISABLED, PROCESS_NAME from DBA_QUEUE_SCHEDULES;SCHEMA QNAME DESTINATION S PROCESS------- ---------- ------------------ - -----------AQADM MULTIPLEQ AQ$_LOCAL N J000 AQ$_LOCAL in the destination column shows that the queue to which we are propagating to is in the same database as the source queue. If the propagation was to a remote (different) database, a database link will be in the DESTINATION column. The entry in the SCHEDULE_DISABLED column, N, means that the schedule is NOT disabled. If Y (yes) appears in this column, propagation is disabled and the schedule will not be executed. If not using Oracle Streams, propagation should resume once you have enabled the schedule by invoking DBMS_AQADM.ENABLE_PROPAGATION_SCHEDULE (for 10.2 Oracle Streams and above, the DBMS_PROPAGATION_ADM.START_PROPAGATION procedure should be used). The PROCESS_NAME is the name of the job queue process currently allocated to execute the schedule. This process is allocated dynamically at execution time. If the PROCESS_NAME column is null (empty) the schedule is not currently executing. You may need to execute this statement a number of times to verify if a process is being allocated. If a process is at some time allocated to the schedule, it is attempting to execute. SQL> select SCHEMA, QNAME, LAST_RUN_DATE, NEXT_RUN_DATE from DBA_QUEUE_SCHEDULES;SCHEMA QNAME LAST_RUN_DATE NEXT_RUN_DATE------ ----- ----------------------- ----------------------- AQADM MULTIPLEQ 13-FEB-2002 13:18:57 13-FEB-2002 13:20:30 In 11g, these dates are expressed in TIMESTAMP WITH TIME ZONE datatypes. If the NEXT_RUN_DATE and NEXT_RUN_TIME columns are null when this statement is executed, the scheduled propagation is currently in progress. If they never change it would suggest that the schedule itself is never executing. If the next scheduled execution is too far away, change the NEXT_TIME parameter of the schedule so that schedules are executed more frequently (assuming that the window is not set to be infinite). Parameters of a schedule can be changed using the DBMS_AQADM.ALTER_PROPAGATION_SCHEDULE call. In 10g and below, scheduling propagation posts a job in the DBA_JOBS view. The columns are more or less the same as DBA_QUEUE_SCHEDULES so you just need to recognize the job and verify that it exists. SQL> select JOB, WHAT from DBA_JOBS where WHAT like '%sys.dbms_aqadm.aq$_propaq(job)%';JOB WHAT---- ----------------- 720 next_date := sys.dbms_aqadm.aq$_propaq(job); For 11g, scheduling propagation posts a job in DBA_SCHEDULER_JOBS instead: SQL> select JOB_NAME from DBA_SCHEDULER_JOBS where JOB_NAME like 'AQ_JOB$_%';JOB_NAME------------------------------AQ_JOB$_41 If no job exists, check DBA_QUEUE_SCHEDULES to make sure that the schedule has not been disabled. For 10g and below, the job number is dynamic for AQ propagation schedules. The procedure that is executed to expedite a propagation schedule runs, removes itself from DBA_JOBS, and then reposts a new job for the next scheduled propagation. The job number should therefore always increment unless the schedule has been set up to run indefinitely. 4.6. Is the Schedule Executing but Failing to Complete? Run the following query: SQL> select FAILURES, LAST_ERROR_MSG from DBA_QUEUE_SCHEDULES;FAILURES LAST_ERROR_MSG------------ -----------------------1 ORA-25207: enqueue failed, queue AQADM.INQ is disabled from enqueueingORA-02063: preceding line from SHANE816 The failures column shows how many times we have attempted to execute the schedule and failed. Oracle will attempt to execute the schedule 16 times after which it will be removed from the DBA_JOBS or DBA_SCHEDULER_JOBS view and the schedule will become disabled. The column DBA_QUEUE_SCHEDULES.SCHEDULE_DISABLED will show 'Y'. For 11g and above, the DBA_SCHEDULER_JOBS.STATE column will show 'BROKEN' for the job corresponding to DBA_QUEUE_SCHEDULES.JOB_NAME. Prior to 10g the back off algorithm for failures was exponential, whereas from 10g onwards it is linear. The propagation will become disabled on the 17th attempt. Only the last execution failure will be reflected in the LAST_ERROR_MSG column. That is, if the schedule fails 5 times for 5 different reasons, only the last set of errors will be recorded in DBA_QUEUE_SCHEDULES. Any errors need to be resolved to allow propagation to continue. If propagation has also become disabled due to 17 failures, first resolve the reason for the error and then re-enable the schedule using the DBMS_AQADM.ENABLE_PROPAGATION_SCHEDULE procedure, or DBMS_PROPAGATION_ADM.START_PROPAGATION if using 10.2 or above Oracle Streams. As soon as the schedule executes successfully the error message entries will be deleted. Oracle does not keep a history of past failures. However, when using Oracle Streams, the errors will be retained in the DBA_PROPAGATION view even after the schedule resumes successfully. See the following note for instructions on how to clear out the errors from the DBA_PROPAGATION view:Document 808136.1 How to clear the old errors from DBA_PROPAGATION view?If a schedule is active and no errors are being reported then the source queue may not have any messages to be propagated. 4.7. Do the Propagation Notification Queue Table and Queue Exist? Check to see that the propagation notification queue table and queue exist and are enabled for enqueue and dequeue. Propagation makes use of the propagation notification queue for handling propagation run-time events, and the messages in this queue are stored in a SYS-owned queue table. This queue should never be stopped or dropped and the corresponding queue table never be dropped. 10g and belowThe propagation notification queue table is of the format SYS.AQ$_PROP_TABLE_n, where 'n' is the RAC instance number, i.e. '1' for a non-RAC environment. This queue and queue table are created implicitly when propagation is first scheduled. If propagation has been scheduled and these objects do not exist, try unscheduling and rescheduling propagation. If they still do not exist contact Oracle Support. SQL> select QUEUE_TABLE from DBA_QUEUE_TABLES2 where QUEUE_TABLE like '%PROP_TABLE%' and OWNER = 'SYS';QUEUE_TABLE------------------------------AQ$_PROP_TABLE_1SQL> select NAME, ENQUEUE_ENABLED, DEQUEUE_ENABLED2 from DBA_QUEUES where owner='SYS'3 and QUEUE_TABLE like '%PROP_TABLE%';NAME ENQUEUE DEQUEUE------------------------------ ------- -------AQ$_PROP_NOTIFY_1 YES YESAQ$_AQ$_PROP_TABLE_1_E NO NO If the AQ$_PROP_NOTIFY_1 queue is not enabled for enqueue or dequeue, it should be so enabled using DBMS_AQADM.START_QUEUE. However, the exception queue AQ$_AQ$_PROP_TABLE_1_E should not be enabled for enqueue or dequeue.11g and aboveThe propagation notification queue table is of the format SYS.AQ_PROP_TABLE, and is created when the database is created. If they do not exist, contact Oracle Support. SQL> select QUEUE_TABLE from DBA_QUEUE_TABLES2 where QUEUE_TABLE like '%PROP_TABLE%' and OWNER = 'SYS';QUEUE_TABLE------------------------------AQ_PROP_TABLESQL> select NAME, ENQUEUE_ENABLED, DEQUEUE_ENABLED2 from DBA_QUEUES where owner='SYS'3 and QUEUE_TABLE like '%PROP_TABLE%';NAME ENQUEUE DEQUEUE------------------------------ ------- -------AQ_PROP_NOTIFY YES YESAQ$_AQ_PROP_TABLE_E NO NO If the AQ_PROP_NOTIFY queue is not enabled for enqueue or dequeue, it should be so enabled using DBMS_AQADM.START_QUEUE. However, the exception queue AQ$_AQ$_PROP_TABLE_E should not be enabled for enqueue or dequeue. 4.8. Does the Remote Queue Exist and is it Enabled for Enqueueing? Check that the remote queue the propagation is transferring messages to exists and is enabled for enqueue: SQL> select DESTINATION from USER_QUEUE_SCHEDULES where QNAME = 'OUTQ';DESTINATION-----------------------------------------------------------------------------"AQADM"."INQ"@M2V102.ESSQL> select OWNER, NAME, ENQUEUE_ENABLED, DEQUEUE_ENABLED from [email protected];OWNER NAME ENQUEUE DEQUEUE-------- ------ ----------- -----------AQADM INQ YES YES 4.9. Do the Target and Source Database Charactersets Differ? If a message fails to propagate, check the database charactersets of the source and target databases. Investigate whether the same message can propagate between the databases with the same characterset or it is only a particular combination of charactersets which causes a problem. 4.10. Check the Queue Table Type Agreement Propagation is not possible between queue tables which have types that differ in some respect. One way to determine if this is the case is to run the DBMS_AQADM.VERIFY_QUEUE_TYPES procedure for the two queues that the propagation operates on. If the types do not agree, DBMS_AQADM.VERIFY_QUEUE_TYPES will return '0'.For AQ propagation between databases which have different NLS_LENGTH_SEMANTICS settings, propagation will not work, unless the queues are Oracle Streams ANYDATA queues.See the following notes for issues caused by lack of type agreement:Document 1079577.1 Advanced Queuing Propagation Fails With "ORA-22370: incorrect usage of method"Document 282987.1 Propagated Messages marked UNDELIVERABLE after Drop and Recreate Of Remote QueueDocument 353754.1 Streams Messaging Propagation Fails between Single and Multi-byte Charactersets when using Chararacter Length Semantics in the ADT 4.11. Enable Propagation Tracing 4.11.1. System Level This is set it in the init.ora/spfile as follows: event="24040 trace name context forever, level 10" and restart the instanceThis event cannot be set dynamically with an alter system command until version 10.2: SQL> alter system set events '24040 trace name context forever, level 10'; To unset the event: SQL> alter system set events '24040 trace name context off'; Debugging information will be logged to job queue trace file(s) (jnnn) as propagation takes place. You can check the trace file for errors, and for statements indicating that messages have been sent. For the most part the trace information is understandable. This trace should also be uploaded to Oracle Support if a service request is created. 4.11.2. Attaching to a Specific Process We can also attach to an existing job queue processes that is running a propagation schedule and trace it individually using the oradebug utility, as follows:10.2 and below connect / as sysdbaselect p.SPID, p.PROGRAM from v$PROCESS p, DBA_JOBS_RUNNING jr, V$SESSION s, DBA_JOBS j where s.SID=jr.SID and s.PADDR=p.ADDR and jr.JOB=j.JOB and j.WHAT like '%sys.dbms_aqadm.aq$_propaq(job)%';-- For the process id (SPID) attach to it via oradebug and generate the following traceoradebug setospid <SPID>oradebug unlimitoradebug Event 10046 trace name context forever, level 12oradebug Event 24040 trace name context forever, level 10-- Trace the process for 5 minutesoradebug Event 10046 trace name context offoradebug Event 24040 trace name context off-- The following command returns the pathname/filename to the file being written tooradebug tracefile_name 11g connect / as sysdbacol PROGRAM for a30select p.SPID, p.PROGRAM, j.JOB_NAMEfrom v$PROCESS p, DBA_SCHEDULER_RUNNING_JOBS jr, V$SESSION s, DBA_SCHEDULER_JOBS j where s.SID=jr.SESSION_ID and s.PADDR=p.ADDR and jr.JOB_NAME=j.JOB_NAME and j.JOB_NAME like '%AQ_JOB$_%';-- For the process id (SPID) attach to it via oradebug and generate the following traceoradebug setospid <SPID>oradebug unlimitoradebug Event 10046 trace name context forever, level 12oradebug Event 24040 trace name context forever, level 10-- Trace the process for 5 minutesoradebug Event 10046 trace name context offoradebug Event 24040 trace name context off-- The following command returns the pathname/filename to the file being written tooradebug tracefile_name 4.11.3. Further Tracing The previous tracing steps only trace the job queue process executing the propagation on the source. At times it is useful to trace the propagation receiver process (the session which is enqueueing the messages into the target queue) on the target database which is associated with the job queue process on the source database.These following queries provide ways of identifying the processes involved in propagation so that you can attach to them via oradebug to generate trace information.In order to identify the propagation receiver process you need to execute the query as a user with privileges to access the v$ views in both the local and remote databases so the database link must connect as a user with those privileges in the remote database. The <DBLINK> in the queries should be replaced by the appropriate database link.The queries have two forms due to the differences between operating systems. The value returned by 'Rem Process' is the operating system identifier of the propagation receiver on the remote database. Once identified, this process can be attached to and traced on the remote database using the commands given in Section 4.11.2.10.2 and below - Windows select pl.SPID "JobQ Process", pl.PROGRAM, sr.PROCESS "Rem Process" from v$PROCESS pl, DBA_JOBS_RUNNING jr, V$SESSION s, DBA_JOBS j, V$SESSION@<DBLINK> sr where s.SID=jr.SID and s.PADDR=pl.ADDR and jr.JOB=j.JOB and j.WHAT like '%sys.dbms_aqadm.aq$_propaq(job)%' and pl.SPID=substr(sr.PROCESS, instr(sr.PROCESS,':')+1); 10.2 and below - Unix select pl.SPID "JobQ Process", pl.PROGRAM, sr.PROCESS "Rem Process" from V$PROCESS pl, DBA_JOBS_RUNNING jr, V$SESSION s, DBA_JOBS j, V$SESSION@<DBLINK> sr where s.SID=jr.SID and s.PADDR=pl.ADDR and jr.JOB=j.JOB and j.WHAT like '%sys.dbms_aqadm.aq$_propaq(job)%' and pl.SPID=sr.PROCESS; 11g - Windows select pl.SPID "JobQ Process", pl.PROGRAM, sr.PROCESS "Rem Process" from V$PROCESS pl, DBA_SCHEDULER_RUNNING_JOBS jr, V$SESSION s, DBA_SCHEDULER_JOBS j, V$SESSION@<DBLINK> sr where s.SID=jr.SESSION_ID and s.PADDR=pl.ADDR and jr.JOB_NAME=j.JOB_NAME and j.JOB_NAME like '%AQ_JOB$_%%' and pl.SPID=substr(sr.PROCESS, instr(sr.PROCESS,':')+1); 11g - Unix select pl.SPID "JobQ Process", pl.PROGRAM, sr.PROCESS "Rem Process" from V$PROCESS pl, DBA_SCHEDULER_RUNNING_JOBS jr, V$SESSION s, DBA_SCHEDULER_JOBS j, V$SESSION@<DBLINK> sr where s.SID=jr.SESSION_ID and s.PADDR=pl.ADDR and jr.JOB_NAME=j.JOB_NAME and j.JOB_NAME like '%AQ_JOB$_%%' and pl.SPID=sr.PROCESS;   5. Additional Troubleshooting Steps for AQ Propagation of User-Enqueued and Dequeued Messages 5.1. Check the Privileges of All Users Involved Ensure that the owner of the database link has the necessary privileges on the aq packages. SQL> select TABLE_NAME, PRIVILEGE from USER_TAB_PRIVS;TABLE_NAME PRIVILEGE------------------------------ ----------------------------------------DBMS_LOCK EXECUTEDBMS_AQ EXECUTEDBMS_AQADM EXECUTEDBMS_AQ_BQVIEW EXECUTEQT52814_BUFFER SELECT Note that when queue table is created, a view called QT<nnn>_BUFFER is created in the SYS schema, and the queue table owner is given SELECT privileges on it. The <nnn> corresponds to the object_id of the associated queue table. SQL> select * from USER_ROLE_PRIVS;USERNAME GRANTED_ROLE ADM DEF OS_------------------------------ ------------------------------ ---- ---- ---AQ_USER1 AQ_ADMINISTRATOR_ROLE NO YES NOAQ_USER1 CONNECT NO YES NOAQ_USER1 RESOURCE NO YES NO It is good practice to configure central AQ administrative user. All admin and processing jobs are created, executed and administered as this user. This configuration is not mandatory however, and the database link can be owned by any existing queue user. If this latter configuration is used, ensure that the connecting user has the necessary privileges on the AQ packages and objects involved. Privileges for an AQ Administrative user Execute on DBMS_AQADM Execute on DBMS_AQ Granted the AQ_ADMINISTRATOR_ROLE Privileges for an AQ user Execute on DBMS_AQ Execute on the message payload Enqueue privileges on the remote queue Dequeue privileges on the originating queue Privileges need to be confirmed on both sites when propagation is scheduled to remote destinations. Verify that the user ID used to login to the destination through the database link has been granted privileges to use AQ. 5.2. Verify Queue Payload Types AQ will not propagate messages from one queue to another if the payload types of the two queues are not verified to be equivalent. An AQ administrator can verify if the source and destination's payload types match by executing the DBMS_AQADM.VERIFY_QUEUE_TYPES procedure. The results of the type checking will be stored in the SYS.AQ$_MESSAGE_TYPES table. This table can be accessed using the object identifier OID of the source queue and the address database link of the destination queue, i.e. [schema.]queue_name[@destination]. Prior to Oracle 9i the payload (message type) had to be the same for all the queue tables involved in propagation. From Oracle9i onwards a transformation can be used so that payloads can be converted from one type to another. The following procedural call made on the source database can verify whether we can propagate between the source and the destination queue tables. connect aq_user1/[email protected] serverout onDECLARErc_value number;BEGINDBMS_AQADM.VERIFY_QUEUE_TYPES(src_queue_name => 'AQ_USER1.Q_1', dest_queue_name => 'AQ_USER2.Q_2',destination => 'dbl_aq_user2.es',rc => rc_value);dbms_output.put_line('rc_value code is '||rc_value);END;/ If propagation is possible then the return code value will be 1. If it is 0 then propagation is not possible and further investigation of the types and transformations used by and in conjunction with the queue tables is required. With regard to comparison of the types the following sql can be used to extract the DDL for a specific type with' %' changed appropriately on the source and target. This can then be compared for the source and target. SET LONG 20000 set pagesize 50 EXECUTE DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM, 'STORAGE',false); SELECT DBMS_METADATA.GET_DDL('TYPE',t.type_name) from user_types t WHERE t.type_name like '%'; EXECUTE DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM, 'DEFAULT'); 5.3. Check Message State and Destination The first step in this process is to identify the queue table associated with the problem source queue. Although you schedule propagation for a specific queue, most of the meta-data associated with that queue is stored in the underlying queue table. The following statement finds the queue table for a given queue (note that this is a multiple-consumer queue table). SQL> select QUEUE_TABLE from DBA_QUEUES where NAME = 'MULTIPLEQ';QUEUE_TABLE --------------------MULTIPLEQTABLE For a small amount of messages in a multiple-consumer queue table, the following query can be run: SQL> select MSG_STATE, CONSUMER_NAME, ADDRESS from AQ$MULTIPLEQTABLE where QUEUE = 'MULTIPLEQ';MSG_STATE CONSUMER_NAME ADDRESS-------------- ----------------------- -------------READY AQUSER2 [email protected] AQUSER1READY AQUSER3 AQADM.INQ In this example we see 2 messages ready to be propagated to remote queues and 1 that is not. If the address column is blank, the message is not scheduled for propagation and can only be dequeued from the queue upon which it was enqueued. The MSG_STATE column values are discussed in Document 102330.1 Advanced Queueing MSG_STATE Values and their Interpretation. If the address column has a value, the message has been enqueued for propagation to another queue. The first row in the example includes a database link (@M2V102.ES). This demonstrates that the message should be propagated to a queue at a remote database. The third row does not include a database link so will be propagated to a queue that resides on the same database as the source queue. The consumer name is the intended recipient at the target queue. Note that we are not querying the base queue table directly; rather, we are querying a view that is available on top of every queue table, AQ$<queue_table_name>.A more realistic query in an environment where the queue table contains thousands of messages is8.0.3-compatible multiple-consumer queue table and all compatibility single-consumer queue tables select count(*), MSG_STATE, QUEUE from AQ$<queue_table_name>  group by MSG_STATE, QUEUE; 8.1.3 and 10.0-compatible queue tables select count(*), MSG_STATE, QUEUE, CONSUMER_NAME from AQ$<queue_table_name>group by MSG_STATE, QUEUE, CONSUMER_NAME; For multiple-consumer queue tables, if you did not see the expected CONSUMER_NAME , check the syntax of the enqueue code and verify the recipients are declared correctly. If a recipients list is not used on enqueue, check the subscriber list in the AQ$_<queue_table_name>_S view (note that a single-consumer queue table does not have a subscriber view. This view records all members of the default subscription list which were added using the DBMS_AQADM.ADD_SUBSCRIBER procedure and also those enqueued using a recipient list. SQL> select QUEUE, NAME, ADDRESS from AQ$MULTIPLEQTABLE_S;QUEUE NAME ADDRESS---------- ----------- -------------MULTIPLEQ AQUSER2 [email protected] AQUSER1 In this example we have 2 subscribers registered with the queue. We have a local subscriber AQUSER1, and a remote subscriber AQUSER2, on the queue INQ, owned by AQADM, at M2V102.ES. Unless overridden with a recipient list during enqueue every message enqueued to this queue will be propagated to INQ at M2V102.ES.For 8.1 style and above multiple consumer queue tables, you can also check the following information at the target: select CONSUMER_NAME, DEQ_TXN_ID, DEQ_TIME, DEQ_USER_ID, PROPAGATED_MSGID from AQ$<queue_table_name> where QUEUE = '<QUEUE_NAME>'; For 8.0 style queues, if the queue table supports multiple consumers you can obtain the same information from the history column of the queue table: select h.CONSUMER, h.TRANSACTION_ID, h.DEQ_TIME, h.DEQ_USER, h.PROPAGATED_MSGIDfrom AQ$<queue_table_name> t, table(t.history) h where t.Q_NAME = '<QUEUE_NAME>'; A non-NULL TRANSACTION_ID indicates that the message was successfully propagated. Further, the DEQ_TIME indicates the time of propagation, the DEQ_USER indicates the userid used for propagation, and the PROPAGATED_MSGID indicates the message ID of the message that was enqueued at the destination. 6. Additional Troubleshooting Steps for Propagation in an Oracle Streams Environment 6.1. Is the Propagation Enabled? For a propagation job to propagate messages, the propagation must be enabled. For Streams, a special view called DBA_PROPAGATION exists to convey information about Streams propagations. If messages are not being propagated by a propagation as expected, then the propagation might not be enabled. To query for this: SELECT p.PROPAGATION_NAME, DECODE(s.SCHEDULE_DISABLED, 'Y', 'Disabled','N', 'Enabled') SCHEDULE_DISABLED, s.PROCESS_NAME, s.FAILURES, s.LAST_ERROR_MSGFROM DBA_QUEUE_SCHEDULES s, DBA_PROPAGATION pWHERE p.DESTINATION_DBLINK = NVL(REGEXP_SUBSTR(s.DESTINATION, '[^@]+', 1, 2), s.DESTINATION) AND s.SCHEMA = p.SOURCE_QUEUE_OWNER AND s.QNAME = p.SOURCE_QUEUE_NAME AND MESSAGE_DELIVERY_MODE = 'PERSISTENT' order by PROPAGATION_NAME; At times, the propagation job may become "broken" or fail to start after an error has been encountered or after a database restart. If an error is indicated by the above query, an attempt to disable the propagation and then re-enable it can be made. In the examples below, for the propagation named STRMADMIN_PROPAGATE where the queue name is STREAMS_QUEUE owned by STRMADMIN and the destination database link is ORCL2.WORLD, the commands would be:10.2 and above exec dbms_propagation_adm.stop_propagation('STRMADMIN_PROPAGATE'); exec dbms_propagation_adm.start_propagation('STRMADMIN_PROPAGATE'); If the above does not fix the problem, stop the propagation specifying the force parameter (2nd parameter on stop_propagation) as TRUE: exec dbms_propagation_adm.stop_propagation('STRMADMIN_PROPAGATE',true); exec dbms_propagation_adm.start_propagation('STRMADMIN_PROPAGATE'); The statistics for the propagation as well as any old error messages are cleared when the force parameter is set to TRUE. Therefore if the propagation schedule is stopped with FORCE set to TRUE, and upon restart there is still an error message in DBA_PROPAGATION, then the error message is current.9.2 or 10.1 exec dbms_aqadm.disable_propagation_schedule('STRMADMIN.STREAMS_QUEUE','ORCL2.WORLD'); exec dbms.aqadm.enable_propagation_schedule('STRMADMIN.STREAMS_QUEUE','ORCL2.WORLD'); If the above does not fix the problem, perform an unschedule of propagation and then schedule_propagation: exec dbms_aqadm.unschedule_propagation('STRMADMIN.STREAMS_QUEUE','ORCL2.WORLD'); exec dbms_aqadm.schedule_propagation('STRMADMIN.STREAMS_QUEUE','ORCL2.WORLD'); Typically if the error from the first query in Section 6.1 recurs after restarting the propagation as shown above, further troubleshooting of the error is needed. 6.2. Check Propagation Rule Sets and Transformations Inspect the configuration of the rules in the rule set that is associated with the propagation process to make sure that they evaluate to TRUE as expected. If not, then the object or schema will not be propagated. Remember that when a negative rule evaluates to TRUE, the specified object or schema will not be propagated. Finally inspect any rule-based transformations that are implemented with propagation to make sure they are changing the data in the intended way.The following query shows what rule sets are assigned to a propagation: select PROPAGATION_NAME, RULE_SET_OWNER||'.'||RULE_SET_NAME "Positive Rule Set",NEGATIVE_RULE_SET_OWNER||'.'||NEGATIVE_RULE_SET_NAME "Negative Rule Set"from DBA_PROPAGATION; The next two queries list the propagation rules and their conditions. The first is for the positive rule set, the second is for the negative rule set: set long 4000select rsr.RULE_SET_OWNER||'.'||rsr.RULE_SET_NAME RULE_SET ,rsr.RULE_OWNER||'.'||rsr.RULE_NAME RULE_NAME,r.RULE_CONDITION CONDITION fromDBA_RULE_SET_RULES rsr, DBA_RULES rwhere rsr.RULE_NAME = r.RULE_NAME and rsr.RULE_OWNER = r.RULE_OWNER and RULE_SET_NAME in(select RULE_SET_NAME from DBA_PROPAGATION) order by rsr.RULE_SET_OWNER, rsr.RULE_SET_NAME;   set long 4000select c.PROPAGATION_NAME, rsr.RULE_SET_OWNER||'.'||rsr.RULE_SET_NAME RULE_SET ,rsr.RULE_OWNER||'.'||rsr.RULE_NAME RULE_NAME,r.RULE_CONDITION CONDITION fromDBA_RULE_SET_RULES rsr, DBA_RULES r ,DBA_PROPAGATION cwhere rsr.RULE_NAME = r.RULE_NAME and rsr.RULE_OWNER = r.RULE_OWNER andrsr.RULE_SET_OWNER=c.NEGATIVE_RULE_SET_OWNER and rsr.RULE_SET_NAME=c.NEGATIVE_RULE_SET_NAMEand rsr.RULE_SET_NAME in(select NEGATIVE_RULE_SET_NAME from DBA_PROPAGATION) order by rsr.RULE_SET_OWNER, rsr.RULE_SET_NAME; 6.3. Determining the Total Number of Messages and Bytes Propagated As in Section 3.1, determining if messages are flowing can be instructive to see whether the propagation is entirely hung or just slow. If the propagation is not in flow control (see Section 6.5.2), but the statistics are incrementing slowly, there may be a performance issue. For Streams implementations two views are available that can assist with this that can show the number of messages sent by a propagation, as well as the number of acknowledgements being returned from the target site: the V$PROPAGATION_SENDER view at the Source site and the V$PROPAGATION_RECEIVER view at the destination site. It is helpful to query both to determine if messages are being delivered to the target. Look for the statistics to increase.Source: select QUEUE_SCHEMA, QUEUE_NAME, DBLINK,HIGH_WATER_MARK, ACKNOWLEDGEMENT, TOTAL_MSGS, TOTAL_BYTESfrom V$PROPAGATION_SENDER; Target: select SRC_QUEUE_SCHEMA, SRC_QUEUE_NAME, SRC_DBNAME, DST_QUEUE_SCHEMA, DST_QUEUE_NAME, HIGH_WATER_MARK, ACKNOWLEDGEMENT, TOTAL_MSGS from V$PROPAGATION_RECEIVER; 6.4. Check Buffered Subscribers The V$BUFFERED_SUBSCRIBERS view displays information about subscribers for all buffered queues in the instance. This view can be queried to make sure that the site that the propagation is propagating to is listed as a subscriber address for the site being propagated from: select QUEUE_SCHEMA, QUEUE_NAME, SUBSCRIBER_ADDRESS from V$BUFFERED_SUBSCRIBERS; The SUBSCRIBER_ADDRESS column will not be populated when the propagation is local (between queues on the same database). 6.5. Common Streams Propagation Errors 6.5.1. ORA-02082: A loopback database link must have a connection qualifier. This error can occur if you use the Streams Setup Wizard in Oracle Enterprise Manager without first configuring the GLOBAL_NAME for your database. 6.5.2. ORA-25307: Enqueue rate too high. Enable flow control DBA_QUEUE_SCHEDULES will display this informational message for propagation when the automatic flow control (10g feature of Streams) has been invoked.Similar to Streams capture processes, a Streams propagation process can also go into a state of 'flow control. This is an informative message that indicates flow control has been automatically enabled to reduce the rate at which messages are being enqueued into at target queue.This typically occurs when the target site is unable to keep up with the rate of messages flowing from the source site. Other than checking that the apply process is running normally on the target site, usually no action is required by the DBA. Propagation and the capture process will be resumed automatically when the target site is able to accept more messages.The following document contains more information:Document 302109.1 Streams Propagation Error: ORA-25307 Enqueue rate too high. Enable flow controlSee the following document for one potential cause of this situation:Document 1097115.1 Oracle Streams Apply Reader is in 'Paused' State 6.5.3. ORA-25315 unsupported configuration for propagation of buffered messages This error typically occurs when the target database is RAC and usually indicates that an attempt was made to propagate buffered messages with the database link pointing to an instance in the destination database which is not the owner instance of the destination queue. To resolve the problem, use queue-to-queue propagation for buffered messages. 6.5.4. ORA-600 [KWQBMCRCPTS101] after dropping / recreating propagation For cause/fixes refer to:Document 421237.1 ORA-600 [KWQBMCRCPTS101] reported by a Qmon slave process after dropping a Streams Propagation 6.5.5. Stopping or Dropping a Streams Propagation Hangs See the following note:Document 1159787.1 Troubleshooting Streams Propagation When It is Not Functioning and Attempts to Stop It Hang 6.6. Streams Propagation-Related Notes for Common Issues Document 437838.1 Streams Specific PatchesDocument 749181.1 How to Recover Streams After Dropping PropagationDocument 368912.1 Queue to Queue Propagation Schedule encountered ORA-12514 in a RAC environmentDocument 564649.1 ORA-02068/ORA-03114/ORA-03113 Errors From Streams Propagation Process - Remote Database is Available and Unschedule/Reschedule Does Not ResolveDocument 553017.1 Stream Propagation Process Errors Ora-4052 Ora-6554 From 11g To 10201Document 944846.1 Streams Propagation Fails Ora-7445 [kohrsmc]Document 745601.1 ORA-23603 'STREAMS enqueue aborted due to low SGA' Error from Streams Propagation, and V$STREAMS_CAPTURE.STATE Hanging on 'Enqueuing Message'Document 333068.1 ORA-23603: Streams Enqueue Aborted Eue To Low SGADocument 363496.1 Ora-25315 Propagating on RAC StreamsDocument 368237.1 Unable to Unschedule Propagation. Streams Queue is InvalidDocument 436332.1 dbms_propagation_adm.stop_propagation hangsDocument 727389.1 Propagation Fails With ORA-12528Document 730911.1 ORA-4063 Is Reported After Dropping Negative Prop.RulesetDocument 460471.1 Propagation Blocked by Qmon Process - Streams_queue_table / 'library cache lock' waitsDocument 1165583.1 ORA-600 [kwqpuspse0-ack] In Streams EnvironmentDocument 1059029.1 Combined Capture and Apply (CCA) : Capture aborts : ORA-1422 after schedule_propagationDocument 556309.1 Changing Propagation/ queue_to_queue : false -> true does does not work; no LCRs propagatedDocument 839568.1 Propagation failing with error: ORA-01536: space quota exceeded for tablespace ''Document 311021.1 Streams Propagation Process : Ora 12154 After Reboot with Transparent Application Failover TAF configuredDocument 359971.1 STREAMS propagation to Primary of physical Standby configuation errors with Ora-01033, Ora-02068Document 1101616.1 DBMS_PROPAGATION_ADM.DROP_PROPAGATION FAILS WITH ORA-1747 7. Performance Issues A propagation may seem to be slow if the queries from Sections 3.1 and 6.3 show that the message statistics are not changing quickly. In Oracle Streams, this more usually is due to a slow apply process at the target rather than a slow propagation. Propagation could be inferred to be slow if the message statistics are changing, and the state of a capture process according to V$STREAMS_CAPTURE.STATE is PAUSED FOR FLOW CONTROL, but an ORA-25307 'Enqueue rate too high. Enable flow control' warning is NOT observed in DBA_QUEUE_SCHEDULES per Section 6.5.2. If this is the case, see the following notes / white papers for suggestions to increase performance:Document 335516.1 Master Note for Streams Performance RecommendationsDocument 730036.1 Overview for Troubleshooting Streams Performance IssuesDocument 780733.1 Streams Propagation Tuning with Network ParametersWhite Paper: http://www.oracle.com/technetwork/database/features/availability/maa-wp-10gr2-streams-performance-130059.pdfWhite Paper: Oracle Streams Configuration Best Practices: Oracle Database 10g Release 10.2, http://www.oracle.com/technetwork/database/features/availability/maa-10gr2-streams-configuration-132039.pdf, See APPENDIX A: USING STREAMS CONFIGURATIONS OVER A NETWORKFor basic AQ propagation, the network tuning in the aforementioned Appendix A of the white paper 'Oracle Streams Configuration Best Practices: Oracle Database 10g Release 10.2' is applicable. References NOTE:102330.1 - Advanced Queueing MSG_STATE Values and their InterpretationNOTE:102771.1 - Advanced Queueing Propagation using PL/SQLNOTE:1059029.1 - Combined Capture and Apply (CCA) : Capture aborts : ORA-1422 after schedule_propagationNOTE:1079577.1 - Advanced Queuing Propagation Fails With "ORA-22370: incorrect usage of method"NOTE:1083608.1 - 11g Streams and Oracle SchedulerNOTE:1087324.1 - ORA-01405 ORA-01422 reported by Adavanced Queueing Propagation schedules after RAC reconfigurationNOTE:1097115.1 - Oracle Streams Apply Reader is in 'Paused' StateNOTE:1101616.1 - DBMS_PROPAGATION_ADM.DROP_PROPAGATION FAILS WITH ORA-1747NOTE:1159787.1 - Troubleshooting Streams Propagation When It is Not Functioning and Attempts to Stop It HangNOTE:1165583.1 - ORA-600 [kwqpuspse0-ack] In Streams EnvironmentNOTE:118884.1 - How to unschedule a propagation schedule stuck in pending stateNOTE:1203544.1 - AQ PROPAGATION ABORTED WITH ORA-600[OCIKSIN: INVALID STATUS] ON SYS.DBMS_AQADM_SYS.AQ$_PROPAGATION_PROCEDURE AFTER UPGRADENOTE:1204080.1 - AQ Propagation Failing With ORA-25329 After Upgraded From 8i or 9i to 10g or 11g.NOTE:219416.1 - Advanced Queuing Propagation fails with ORA-22922NOTE:222992.1 - DBMS_AQADM.DISABLE_PROPAGATION_SCHEDULE Returns ORA-24082NOTE:253131.1 - Concurrent Writes May Corrupt LOB Segment When Using Auto Segment Space Management (ORA-1555)NOTE:282987.1 - Propagated Messages marked UNDELIVERABLE after Drop and Recreate Of Remote QueueNOTE:298015.1 - Kwqjswproc:Excep After Loop: Assigning To SelfNOTE:302109.1 - Streams Propagation Error: ORA-25307 Enqueue rate too high. Enable flow controlNOTE:311021.1 - Streams Propagation Process : Ora 12154 After Reboot with Transparent Application Failover TAF configuredNOTE:332792.1 - ORA-04061 error relating to SYS.DBMS_PRVTAQIP reported when setting up StatspackNOTE:333068.1 - ORA-23603: Streams Enqueue Aborted Eue To Low SGANOTE:335516.1 - Master Note for Streams Performance RecommendationsNOTE:353325.1 - ORA-24056: Internal inconsistency for QUEUE and destination NOTE:353754.1 - Streams Messaging Propagation Fails between Single and Multi-byte Charactersets when using Chararacter Length Semantics in the ADT.NOTE:359971.1 - STREAMS propagation to Primary of physical Standby configuation errors with Ora-01033, Ora-02068NOTE:363496.1 - Ora-25315 Propagating on RAC StreamsNOTE:365093.1 - ORA-07445 [kwqppay2aqe()+7360] reported on Propagation of a Transformed MessageNOTE:368237.1 - Unable to Unschedule Propagation. Streams Queue is InvalidNOTE:368912.1 - Queue to Queue Propagation Schedule encountered ORA-12514 in a RAC environmentNOTE:421237.1 - ORA-600 [KWQBMCRCPTS101] reported by a Qmon slave process after dropping a Streams PropagationNOTE:436332.1 - dbms_propagation_adm.stop_propagation hangsNOTE:437838.1 - Streams Specific PatchesNOTE:460471.1 - Propagation Blocked by Qmon Process - Streams_queue_table / 'library cache lock' waitsNOTE:463820.1 - Streams Combined Capture and Apply in 11gNOTE:553017.1 - Stream Propagation Process Errors Ora-4052 Ora-6554 From 11g To 10201NOTE:556309.1 - Changing Propagation/ queue_to_queue : false -> true does does not work; no LCRs propagatedNOTE:564649.1 - ORA-02068/ORA-03114/ORA-03113 Errors From Streams Propagation Process - Remote Database is Available and Unschedule/Reschedule Does Not ResolveNOTE:566622.1 - ORA-22275 when propagating >4K AQ$_JMS_TEXT_MESSAGEs from 9.2.0.8 to 10.2.0.1NOTE:727389.1 - Propagation Fails With ORA-12528NOTE:730036.1 - Overview for Troubleshooting Streams Performance IssuesNOTE:730911.1 - ORA-4063 Is Reported After Dropping Negative Prop.RulesetNOTE:731292.1 - ORA-25215 Reported On Local Propagation When Using Transformation with ANYDATA queue tablesNOTE:731539.1 - ORA-29268: HTTP client error 401 Unauthorized Error when the AQ Servlet attempts to Propagate a message via HTTPNOTE:745601.1 - ORA-23603 'STREAMS enqueue aborted due to low SGA' Error from Streams Propagation, and V$STREAMS_CAPTURE.STATE Hanging on 'Enqueuing Message'NOTE:749181.1 - How to Recover Streams After Dropping PropagationNOTE:780733.1 - Streams Propagation Tuning with Network ParametersNOTE:787367.1 - ORA-22275 reported on Propagating Messages with LOB component when propagating between 10.1 and 10.2NOTE:808136.1 - How to clear the old errors from DBA_PROPAGATION view ?NOTE:827184.1 - AQ Propagation with CLOB data types Fails with ORA-22990NOTE:827473.1 - How to alter propagation from queue_to_queue to queue_to_dblinkNOTE:839568.1 - Propagation failing with error: ORA-01536: space quota exceeded for tablespace ''NOTE:846297.1 - AQ Propagation Fails : ORA-00600[kope2upic2954] or Ora-00600[Kghsstream_copyn]NOTE:944846.1 - Streams Propagation Fails Ora-7445 [kohrsmc]

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  • What is Agile Modeling and why do I need it?

    What is Agile Modeling and why do I need it? Agile Modeling is an add-on to existing agile methodologies like Extreme programming (XP) and Rational Unified Process (RUP). Agile Modeling enables developers to develop a customized software development process that actually meets their current development needs and is flexible enough to adjust in the future. According to Scott Ambler, Agile Modeling consists of five core values that enable this methodology to be effective and light weight Agile Modeling Core Values: Communication Simplicity Feedback Courage Humility Communication is a key component to any successful project. Open communication between stakeholder and the development team is essential when developing new applications or maintaining legacy systems. Agile models promote communication amongst software development teams and stakeholders. Furthermore, Agile Models provide a common understanding of an application for members of a software development team allowing them to have a universal common point of reference. The use of simplicity in Agile Models enables the exploration of new ideas and concepts through the use of basic diagrams instead of investing the time in writing tens or hundreds of lines of code. Feedback in regards to application development is essential. Feedback allows a development team to confirm that the development path is on track. Agile Models allow for quick feedback from shareholders because minimal to no technical expertise is required to understand basic models. Courage is important because you need to make important decisions and be able to change direction by either discarding or refactoring your work when some of your decisions prove inadequate, according to Scott Ambler. As a member of a development team, we must admit that we do not know everything even though some of us think we do. This is where humility comes in to play. Everyone is a knowledge expert in their own specific domain. If you need help with your finances then you would consult an accountant. If you have a problem or are in need of help with a topic why would someone not consult with a subject expert? An effective approach is to assume that everyone involved with your project has equal value and therefore should be treated with respect. Agile Model Characteristics: Purposeful Understandable Sufficiently Accurate Sufficiently Consistent Sufficiently Detailed Provide Positive Value Simple as Possible Just Fulfill Basic Requirements According to Scott Ambler, Agile models are the most effective possible because the time that is invested in the model is just enough effort to complete the job. Furthermore, if a model isn’t good enough yet then additional effort can be invested to get more value out of the model. However if a model is good enough, for the current needs, or surpass the current needs, then any additional work done on the model would be a waste. It is important to remember that good enough is in the eye of the beholder, so this can be tough. In order for Agile Models to work effectively Active Stakeholder need to participation in the modeling process. Finally it is also very important to model with others, this allows for additionally input ensuring that all the shareholders needs are reflected in the models. How can Agile Models be incorporated in to our projects? Agile Models can be incorporated in to our project during the requirement gathering and design phases. As requirements are gathered the models should be updated to incorporate the new project details as they are defined and updated. Additionally, the Agile Models created during the requirement phase can be the bases for the models created during the design phase.  It is important to only add to the model when the changes fit within the agile model characteristics and they do not over complicate the design.

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  • The Evolution Of C#

    - by Paulo Morgado
    The first release of C# (C# 1.0) was all about building a new language for managed code that appealed, mostly, to C++ and Java programmers. The second release (C# 2.0) was mostly about adding what wasn’t time to built into the 1.0 release. The main feature for this release was Generics. The third release (C# 3.0) was all about reducing the impedance mismatch between general purpose programming languages and databases. To achieve this goal, several functional programming features were added to the language and LINQ was born. Going forward, new trends are showing up in the industry and modern programming languages need to be more: Declarative With imperative languages, although having the eye on the what, programs need to focus on the how. This leads to over specification of the solution to the problem in hand, making next to impossible to the execution engine to be smart about the execution of the program and optimize it to run it more efficiently (given the hardware available, for example). Declarative languages, on the other hand, focus only on the what and leave the how to the execution engine. LINQ made C# more declarative by using higher level constructs like orderby and group by that give the execution engine a much better chance of optimizing the execution (by parallelizing it, for example). Concurrent Concurrency is hard and needs to be thought about and it’s very hard to shoehorn it into a programming language. Parallel.For (from the parallel extensions) looks like a parallel for because enough expressiveness has been built into C# 3.0 to allow this without having to commit to specific language syntax. Dynamic There was been lots of debate on which ones are the better programming languages: static or dynamic. The fact is that both have good qualities and users of both types of languages want to have it all. All these trends require a paradigm switch. C# is, in many ways, already a multi-paradigm language. It’s still very object oriented (class oriented as some might say) but it can be argued that C# 3.0 has become a functional programming language because it has all the cornerstones of what a functional programming language needs. Moving forward, will have even more. Besides the influence of these trends, there was a decision of co-evolution of the C# and Visual Basic programming languages. Since its inception, there was been some effort to position C# and Visual Basic against each other and to try to explain what should be done with each language or what kind of programmers use one or the other. Each language should be chosen based on the past experience and familiarity of the developer/team/project/company and not by particular features. In the past, every time a feature was added to one language, the users of the other wanted that feature too. Going forward, when a feature is added to one language, the other will work hard to add the same feature. This doesn’t mean that XML literals will be added to C# (because almost the same can be achieved with LINQ To XML), but Visual Basic will have auto-implemented properties. Most of these features require or are built on top of features of the .NET Framework and, the focus for C# 4.0 was on dynamic programming. Not just dynamic types but being able to talk with anything that isn’t a .NET class. Also introduced in C# 4.0 is co-variance and contra-variance for generic interfaces and delegates. Stay tuned for more on the new C# 4.0 features.

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  • Silverlight Cream for December 13, 2010 -- #1010

    - by Dave Campbell
    In this Issue: Rénald Nollet, Benjamin Gavin, Dennis Doomen, Tim Greenfield, Mike Taulty, Jeff Blankenburg, Michael Crump, Laurent Duveau, Dragos Manolescu, KeyboardP, Yochay Kiriaty. Above the Fold: Silverlight: "Silverlight RIA Services and Basic, Anonymous Authentication" Benjamin Gavin WP7: "lving Circular Navigation in Windows Phone Silverlight Applications" Yochay Kiriaty SQL Azure: "SQL Azure Database Manager – Part 1 : How to connect to your SQL Azure DB" Rénald Nollet Shoutouts: Yochay Kiriaty has a post up on the Windows Phone Devloper Blog about open source (MSPL) projects helping WP7 devs: Windows Phone Recipes – Helping the Community Jesse Liberty's latest Yet Another Podcast is up and thie time it's Joe Stagner: Yet Another Podcast #18 – Joe Stagner Josh Schwartzberg sent me this link to what is apparently his yearly web-only rock Christmas album: MetalXmas... done in Silverlight and RIA Services From SilverlightCream.com: SQL Azure Database Manager – Part 1 : How to connect to your SQL Azure DB Rénald Nollet posted Part 1 of a series on a SQL Azure database manager all in Silverlight... has a live demo running, some description, and is making us wait for the next part! Silverlight RIA Services and Basic, Anonymous Authentication Benjamin Gavin has a quick post up resolving a basic RIA Services problem that I bet a lot of folks are looking for the answer on... like 500 series errors... cool little find he ferreted out... A night of Silverlight, WPF, unit testing and Caliburn Micro Dennis Doomen in concert with his employer gave a couple talks at the local DotNED user group, and covered literally a cornucopia of topics... slides, and example code for both talks... lotsa material here... Tim Greenfield on PuzzleTouch WP7 Application Tim Greenfield is the latest WP7 app developer to be interviewed by the SilverlightShow crew... lots of interesting comments and insight from Tim. Rebuilding the PDC 2010 Silverlight Application (Part 4) Mike Taulty has part 4 of his PDC 2010 Silverlight app construction project up and is taking the app into Blend, and the considerations that brought to the table. What I Learned In WP7 – Issue #2 Jeff Blankenburg continues his "What I Learned" series with this discussion about fonts, the Non-Linear Navigation service I mention below, and possible WP7 jobs. Part 3 of 4 : Tips/Tricks for Silverlight Developers Michael Crump has Part 3 of his Tips/Tricks up today. Lots of goodies this time: underlining in a TextBlock, getting browser info, startup params, VisualTreeHelper, and child windows. My Windows Phone 7 presentation in Montreal Laurent Duveau gave a WP7 presentation in Montreal as part of the Microsoft Windows Phone 7 Developer's Briefing, and has posted his materials and slide deck WP7 Code: Mocking Event Streams with IEnumerable Dragos Manolescu has a very cool post up on using IEnumerable to Mock event streams by leveraging the IObservable/IEnumerable duality, and uses the 2D bubble app that you can run and test in the emulator without needing an accelerometer Transparent Wallpapers – Video Tutorial KeyboardP has had so many queries about his Transparent wallpaper for WP7 that he produced a video tutorial for it... Solving Circular Navigation in Windows Phone Silverlight Applications Yochay Kiriaty discusses the first recipe they are releasing ... see the shoutout above, a Nonlinear Navigation Service ... to help with apps that have loops in navigation. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • Microsoft Silverlight 4 Business Application Development: Beginner's Guide

    Build enterprise-ready business applications with Silverlight An introduction to building enterprise-ready business applications with Silverlight quickly. Get hold of the basic tools and skills needed to get started in Silverlight application development. Integrate different media types, taking the RIA experience further with Silverlight, and much more! Rapidly manage business focused controls, data, and business logic connectivity. A suite of business applications will be built over the course of the book and all examples will be geared around real-world useful application developments, enabling .NET developers to focus on getting started in business application development using Silverlight. In Detail Microsoft Silverlight is a programmable web browser plug-in that enables features including animation, vector graphics, and audio-video playback--features that characterize Rich Internet Applications. Silverlight makes possible the development of RIA applications in familiar .NET languages such as C# and VB.NET. Silverlight is a great (and growing) Line of Business platform and is increasingly being used to build business applications. Silverlight 3 made a big step in LOB; Silverlight 4 builds upon this further. This book will enable .NET developers to feel the pulse of business application development with Silverlight quickly. This book is not a general Silverlight 3/4 overview book. It is uniquely aimed at developers who require an introduction to building business applications with Silverlight. This book will focus on building a suite of real-world, useful business applications in a practical hands-on approach. This book is for .Net developers, providing the answers to many questions that are encountered when creating business applications in Silverlight, ultimately enabling rapid development with ease! This book teaches you how to build business applications with Silverlight 3 and 4. Building a suite of applications, it begins by introducing you to the basic tools and skills needed to get started in Silverlight development. It then dives deeply into the world of business application development, covering all the required concepts needed to build sophisticated business applications and provide a rich user experience. Chapters include: building a public website, adding rich media to the website, incorporating RIA into your website, and among others. By following the practical steps in this book, you will learn what's needed to create rich business applications--from the creation of a Silverlight application, to enhancing your application with rich media and connecting your Silverlight application to various Data Sources. What you will learn from this book Learn the basic tools and skills needed to get started in Silverlight 4 business application development. Discover how to enhance your Silverlight business applications with rich data such as sound and video. Know when and how to customize your data in Silverlight using important data controls. Understand how your Silverlight business applications can connect to various Data Sources. Deliver your Silverlight business application in a variety of forms.   Interesting? Read the chapter 1 Getting Started for free!! Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Oracle Fusion CRM Implementation Bootcamp for EMEA Systems Integrators - Paris July 24-26th

    - by Richard Lefebvre
    To support partner success and increase win potential with Fusion CRM, we are organizing a unique bootcamp on Fusion CRM intended for Oracle EMEA partners on July 24th to 26th. Join us for this outstanding Bootcamp and learn from Oracle Corporation in-depth know-how on Fusion CRM. The official announcement will be forthcoming, yet we wanted you to determine the appropriate candidate to attend this workshop. Further to this we will send the actual invitation to the selected candidate. Due to the limited number of seats, we will be limiting the number of registrations per SI company and will be selecting the participants. If you are interested to have one or more representatives of your company to attend this bootcamp, please send an email to [email protected] by June 18th indicating the name and email address of the participants you would like to nominate, ranked by priority. What will we cover: This Bootcamp presents the fundamental concepts of the Oracle Fusion CRM applications. It introduces you to each functional area of the product, how it is used, and what you need to consider when implementing it for an organization. While we do examine implementation considerations, we do not address the detailed steps of implementation. Instead, we direct you to the relevant resources to learn more. Topics covered: Fusion CRM Introduction Fusion CRM Security Introduction Fusion Functional Setup Manager Introduction Customer Model Introduction Customer Center Introduction Customer Data Management Introduction Marketing & Campaigns Introduction Lead Management Introduction Territory Management Introduction Territory Modeling Introduction with Exercise Opportunity Management Introduction Forecasting Introduction Analytics Introduction CRM For Microsoft Outlook Introduction Customizing with Composers Introduction Roundtable Discussions, and time for hands-on labs (day 2, 3, 4) Next Steps, available resources, ongoing learning path, partner environments, keeping in touch and feedback Bootcamp Goals: Enable a new Fusion CRM implementation team member to: Describe the scope of Oracle Fusion CRM applications Describe the basic security model Describe the customer model Perform common sales and marketing user transactions Access and navigate the Functional Setup Manager Model territories in Fusion CRM using sample business requirements Do necessary planning before implementing the offerings and options Describe the analytics available with the Fusion CRM product Describe the basic page customizations that can be done to meet business requirements Find documentation and other courses to assist in performing setup tasks Expectations: This Bootcamp program should prime the SI organization implementation consultants to attain the basic skills necessary to support a consulting practice in the delivery, scoping, pricing, and planning of your Fusion CRM Implementations. Oracle University will begin to offer additional deep skill training, starting this summer, designed to follow the Introduction Bootcamp. Participants will be expected to participate in labs, exercises, workshops and roundtable discussions with the Oracle Product Managers. Who should attend: This class is designed for your lead CRM Implementation consultants, those who will support your Fusion CRM consulting practice as it grows. These individuals may be members of a centre of excellence, or skills leadership office. The individual who is attending the bootcamp must have prior experience implementing a CRM solution. Intended Audience: Oracle Diamond, Platinum and Gold Level SIs (Top SIs) with specialization in Oracle Applications CRM implementations, with a commitment to achieving Fusion CRM Implementation Specialization. Commitment expressed through an investment in a Center of Excellence/Innovation Center for Fusion CRM Applications. Individuals who will support the implementation practice as it is forming and will deliver Fusion CRM On Premise and Cloud Services implementations. Functional practice leaders, the future Fusion Application Wizards within the SI's organization. This Bootcamp is designed for people who: Will deliver Fusion CRM implementations Have had little or no exposure to Fusion CRM applications Are familiar with at least one other CRM application Have a business analyst level of technical background Prerequisites: Please note, that participants will be asked to take self-service-trainings (video format) and pass the related assessments prior to joining the Bootcamp. Fees: This event is FREE of charge for Oracle partners. When: 24 July – 26 July, 2012 (8:30 - 18:00 each day, including the last day; with recommended but optional evening events on all three days from 18:00 - 20:00 hrs) Where: Paris, France (Location to be defined) Travel: To make your travel hassel free, we kindly suggest you to plan your arrival to Paris on July 23rd and your departure on the 27th. Agenda: The final agenda and registration details will be issued closer to the event date.  

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  • Partner outreach on the Oracle Fusion Applications user experience begins

    - by mvaughan
    by Misha Vaughan, Architect, Applications User Experience I have been asked the question repeatedly since about December of last year: “What is the Applications User Experience group doing about partner outreach?”  My answer, at the time, was: “We are thinking about it.”  My colleagues and I were really thinking about the content or tools that the Applications UX group should be developing. What would be valuable to our partners? What will actually help grow their applications business, and fits within the applications user experience charter?In the video above, you’ll hear Jeremy Ashley, vice president of the Applications User Experience team, talk about two fundamental initiatives that our group is working on now that speaks straight to partners.  Special thanks to Joel Borellis, Kelley Greenly, and Steve Hoodmaker for helping to make this video happen so flawlessly. Steve was responsible for pulling together a day of Oracle Fusion Applications-oriented content, including David Bowin, Director, Fusion Applications Strategy, on some of the basic benefits of Oracle Fusion Applications.  Joel Borellis, Group Vice President, Partner Enablement, and David Bowin in the Oracle Studios.Nigel King, Vice President Applications Functional Architecture, was also on the list, talking about co-existence opportunities with Oracle Fusion Applications.Me and Nigel King, just before his interview with Joel. Fusion Applications User Experience 101: Basic education  Oracle has invested an enormous amount of intellectual and developmental effort in the Oracle Fusion Applications user experience. Find out more about that at the Oracle Partner Network Fusion Learning Center (Oracle ID required). What you’ll learn will help you uncover how, exactly, Oracle made Fusion General Ledger “sexy,” and that’s a direct quote from Oracle Ace Director Debra Lilley, of Fujitsu. In addition, select Applications User Experience staff members, as well as our own Fusion User Experience Advocates,  can provide a briefing to our partners on Oracle’s investment in the Oracle Fusion Applications user experience. Looking forward: Taking the best of the Fusion Applications UX to your customersBeyond a basic orientation to one of the key differentiators for Oracle Fusion Applications, we are also working on partner-oriented training.A question we are often getting right now is: “How do I help customers build applications that look like Fusion?” We also hear: “How do I help customers build applications that take advantage of the next-generation design work done in Fusion?”Our answer to this is training and a tool – our user experience design patterns – these are a set of user experience best-practices. Design patterns are re-usable, usability-tested, user experience components that make creating Fusion Applications-like experiences straightforward.  It means partners can leverage Oracle’s investment, but also gain an advantage by not wasting time solving a problem we’ve already solved. Their developers can focus on helping customers tackle the harder development challenges. Ultan O’Broin, an Apps UX team member,  and I are working with Kevin Li and Chris Venezia of the Oracle Platform Technology Services team, as well as Grant Ronald in Oracle ADF, to bring you some of the best “how-to” UX training, customized for your local area. Our first workshop will be in EMEA. Stay tuned for an assessment and feedback from the event.

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  • Getting Started with StreamInsight 2.1

    - by Roman Schindlauer
    If you're just beginning to get familiar with StreamInsight, you may be looking for a way to get started. What are the basics? How can I get my first StreamInsight application running so I can see how it works? Where is the 'front door' that will get me going? If that describes you, then this blog entry might be just what you need. If you're already a StreamInsight wiz, keep reading anyway - you may find some helpful links here that you weren't aware of. But here's what we'd like from you experienced readers in particular: if you know of other good resources that we missed, please feel free to add them in the comments below. We appreciate you sharing your expertise. The Book The basic documentation for StreamInsight is located in the MSDN Library (Microsoft StreamInsight 2.1). You'll notice that previous versions of StreamInsight are still there (1.2 and 2.0), but if you're just getting started you can stick to the 2.1 section. The documentation has been organized to function as reference material, which is fine after you're familiar with the technology. But if you're trying to learn the basics, you might want to take a different path instead of just starting at the top. The following is one map you can use. What Is StreamInsight? Here is a sequence of topics that should give you a good overview of what StreamInsight is and how it works: Overview answers the question, "what is it?" StreamInsight Server Architecture gives you a quick look at a high-level architectural drawing StreamInsight Concepts lays out an overview of the basic components Deploying StreamInsight Entities to a StreamInsight Server describes the mechanics of how these components work together Getting an Example Running Once you have this background, go ahead and install StreamInsight and get a basic example up and running: Installation download and install the software StreamInsight Examples walk through a set of 3 simple StreamInsight applications that work together to demonstrate what you learned in the topics above; you can copy and paste the code into Visual Studio, compile, and run That's it - you now have a real, functioning StreamInsight system! Now that you have a handle on the basics, you might want to start digging deeper. Digging Deeper Here's a suggested path through the documentation to help you understand the next layer of StreamInsight technologies: Using Event Sources and Event Sinks sources supply data and sinks consume it; this topic gives you an overview of how they work Publishing and Connecting to the StreamInsight Server practical details on how to set up a StreamInsight server A Hitchhiker’s Guide to StreamInsight 2.1 Queries queries are the heart of how StreamInsight performs data analytics, and this whitepaper will help you really understand how they work Using StreamInsight LINQ root through this section for technical details on specific query components Using the StreamInsight Event Flow Debugger in addition to troubleshooting, the debugger is a great way to learn more about what goes on inside a StreamInsight application And Even Deeper Finally, to get a handle on some of the more complex things you can do with StreamInsight, dig into these: Input and Output Adapters adapters can be useful for handling more complex sources and sinks Building Resilient StreamInsight Applications a resilient application is able to recover from system failures Operations this section will help you monitor and troubleshoot a running StreamInsight system The StreamInsight Community As you're designing and developing your StreamInsight solutions, you probably will find it helpful to see working examples or to learn tips and tricks from others. Or maybe you need a place to post a vexing question. Here are some community resources that we have found useful. If you know of others, please add them in the comments below. Code samples and tools Official StreamInsight code samples Introduction to LinqPad Driver for StreamInsight 2.1 - LinqPad is a very useful tool for developing queries The following case studies are based on earlier versions of StreamInsight, but they still are useful examples: Microsoft Media Analytics - real-time monitoring and analytic Edgenet - responding to information from multiple source ICONICS - managing energy usage Blogs Microsoft StreamInsight Ruminations of J.net Richard Seroter's Architecture Musings pluralsight Forums MSDN StreamInsight Forum stackoverflow Training Microsoft StreamInsight Fundamentals (“Introducing StreamInsight” is free) from pluralsight Twitter @streaminsight   You’re a StreamInsight Expert That should get you going. Please add any other resources you have found useful in the comments below.   Regards, The StreamInsight Team

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  • Hide and Unhide Worksheets and Workbooks in Excel 2007 & 2010

    - by DigitalGeekery
    Hiding worksheets can be a simple way to protect data in Excel, or just a way reduce the clutter of a some tabs. Here are a couple very easy ways to hide and unhide worksheets and workbooks in Excel 2007 / 2010. Hiding a Worksheet Select the Worksheet you’d like to hide by clicking on the tab at the bottom. By holding down the Ctrl key while clicking you can select multiple tabs at one time. On the Home tab, click on Format, which can be found in the Cells group. Under Visibility,  select Hide & Unhide, then Hide Sheet.   You can also simply right-click on the tab, and select Hide.   Your worksheet will no longer be visible, however, the data contained in the worksheet can still be referenced on other worksheets.   Unhide a Worksheet To unhide a worksheet, you just do the opposite. On the Home tab, click on Format in the Cells group and then under Visibility,  select Hide & Unhide, then Unhide Sheet.   Or, you can right-click on any visible tab, and select Unhide.   In the Unhide pop up window, select the worksheet to unhide and click “OK.” Note: Although you can hide multiple sheets at once, you can only unhide one sheet at a time. Very Hidden Mode While hidden mode is nice, it’s not exactly ultra-secure. If you’d like to pump the security up a notch, there is also Very Hidden mode. To access Very Hidden setting, we’ll have to use the built-in Visual Basic Editor by hitting the Alt + F11 keys. Select the worksheet you wish to hide from the dropdown list under Properties or by single clicking the worksheet in the VBAProject window. Next, set the Visible property to  2 – xlSheetVeryHidden. Close out of the Visual Basic Editor when finished.   When the Very Hidden attribute is set on a worksheet, Unhide Sheet is still unavailable from within the Format setting on the Home tab.   To remove the Very Hidden attribute and display the worksheet again, go back into the Visual Basic Editor by hitting Alt + F11 again and setting the Visible property back to –1 – xlSheetVisible.  Close out of the Editor when finished. Hiding a Workbook To hide the entire Workbook, select the View tab, and then click the Hide button. You’ll see the Workbook has disappeared. Unhide a Workbook Select the View tab and click Unhide… … and your Workbook will be visible again.   Just a few simple ways to hide and unhide your Excel worksheets and workbooks. Similar Articles Productive Geek Tips How To Copy Worksheets in Excel 2007 & 2010Add Background Pictures To Excel 2007 WorksheetsMake Row Labels In Excel 2007 Freeze For Easier ReadingImport Microsoft Access Data Into ExcelMagnify Selected Cells In Excel 2007 TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Discover Latest Android Apps On AppBrain The Ultimate Guide For YouTube Lovers Will it Blend? iPad Edition Penolo Lets You Share Sketches On Twitter Visit Woolyss.com for Old School Games, Music and Videos Add a Custom Title in IE using Spybot or Spyware Blaster

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  • Surviving MATLAB and R as a Hardcore Programmer

    - by dsimcha
    I love programming in languages that seem geared towards hardcore programmers. (My favorites are Python and D.) MATLAB is geared towards engineers and R is geared towards statisticians, and it seems like these languages were designed by people who aren't hardcore programmers and don't think like hardcore programmers. I always find them somewhat awkward to use, and to some extent I can't put my finger on why. Here are some issues I have managed to identify: (Both): The extreme emphasis on vectors and matrices to the extent that there are no true primitives. (Both): The difficulty of basic string manipulation. (Both): Lack of or awkwardness in support for basic data structures like hash tables and "real", i.e. type-parametric and nestable, arrays. (Both): They're really, really slow even by interpreted language standards, unless you bend over backwards to vectorize your code. (Both): They seem to not be designed to interact with the outside world. For example, both are fairly bulky programs that take a while to launch and seem to not be designed to make simple text filter programs easy to write. Furthermore, the lack of good string processing makes file I/O in anything but very standard forms near impossible. (Both): Object orientation seems to have a very bolted-on feel. Yes, you can do it, but it doesn't feel much more idiomatic than OO in C. (Both): No obvious, simple way to get a reference type. No pointers or class references. For example, I have no idea how you roll your own linked list in either of these languages. (MATLAB): You can't put multiple top level functions in a single file, encouraging very long functions and cut-and-paste coding. (MATLAB): Integers apparently don't exist as a first class type. (R): The basic builtin data structures seem way too high level and poorly documented, and never seem to do quite what I expect given my experience with similar but lower level data structures. (R): The documentation is spread all over the place and virtually impossible to browse or search. Even D, which is often knocked for bad documentation and is still fairly alpha-ish, is substantially better as far as I can tell. (R): At least as far as I'm aware, there's no good IDE for it. Again, even D, a fairly alpha-ish language with a small community, does better. In general, I also feel like MATLAB and R could be easily replaced by plain old libraries in more general-purpose langauges, if sufficiently comprehensive libraries existed. This is especially true in newer general purpose languages that include lots of features for library writers. Why do R and MATLAB seem so weird to me? Are there any other major issues that you've noticed that may make these languages come off as strange to hardcore programmers? When their use is necessary, what are some good survival tips? Edit: I'm seeing one issue from some of the answers I've gotten. I have a strong personal preference, when I analyze data, to have one script that incorporates the whole pipeline. This implies that a general purpose language needs to be used. I hate having to write a script to "clean up" the data and spit it out, then another to read it back in a completely different environment, etc. I find the friction of using MATLAB/R for some of my work and a completely different language with a completely different address space and way of thinking for the rest to be a huge source of friction. Furthermore, I know there are glue layers that exist, but they always seem to be horribly complicated and a source of friction.

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  • Indentify Codecs & Technical Information About Video Files

    - by DigitalGeekery
    Have you ever wanted to play an audio or video file but didn’t have the proper codec installed? Today we’ll show how to determine codecs, along with a host of other technical details about your media files with MediaInfo. Installation Download and install MediaInfo. You can find the download link at the bottom of the page. Note: When installing MediaInfo there is a recommended software bundle which you can opt out of by selecting Do not install option. Each recommended software choice may be different, like in this example it offers Spyware Terminator. The cool thing though is they use Open Candy which opts you out of the install. Just double check to make sure you’re not installing extra crapware. Using MediaInfo The first time you run MediaInfo it will display the Preferences window. There are various option such as language, output format, and whether or not you want MediaInfo to check for new versions. Click OK. Select a file or folder to analyze by clicking on the File or Folder icons on the left of the application window or by selecting File > Open from the menu. You can also drag and drop a file directly onto the application. MediaInfo will display details of your media file. In Basic view, you’ll see basic information. Notice in the example below the video and audio codecs, along with file size, running time of the media file, and even the application used to create the video file (Writing application).    You can switch to some of the other views by selecting View from the Menu and choosing form the dropdown list.   Sheet View will present the information a bit more clearly. You can see in the example below that the video and audio codec are listing in clearly identified columns. (AVC is often more commonly referred to H.264.)   Tree View is perhaps the most detailed. You can see from the example below the codec used for this AVI file is XviD.   Scrolling down even further you’ll see additional information like video and audio bit rates, frame rate, aspect ratio, and more.   In Basic View (and also in Sheet view) you can click to find a player for your file. In this instance with an MP4 file, it took me to the download page for Quicktime. This is by no means the only media player for this file, but if you are stuck for how to play a media file, this will forward you to a solution that works. You can do the same thing with Video codec. Click Go to the web site of this video codec to find a download.   MediaInfo is a simple but powerful tool that can be used to discover the details of a media file, or just to find a compatible codec. It works with most any video file type and is available for Windows, Mac, and Linux. Some Mac and Linux versions, however, are currently command line only. Download MediaInfo Similar Articles Productive Geek Tips How to Convert Videos to 3GP for Mobile PhonesFix for VLC Skipping and Lagging Playing High-Def Video FilesUsing VLC Player Under VistaUse Your Mac Mini as a Media Server Part 2How to Play .OGM Video Files in Windows Vista TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Xobni Plus for Outlook All My Movies 5.9 CloudBerry Online Backup 1.5 for Windows Home Server Snagit 10 2010 World Cup Schedule Boot Snooze – Reboot and then Standby or Hibernate Customize Everything Related to Dates, Times, Currency and Measurement in Windows 7 Google Earth replacement Icon (Icons we like) Build Great Charts in Excel with Chart Advisor tinysong gives a shortened URL for you to post on Twitter (or anywhere)

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  • Abstraction, Politics, and Software Architecture

    Abstraction can be defined as a general concept and/or idea that lack any concrete details. Throughout history this type of thinking has led to an array of new ideas and innovations as well as increased confusion and conspiracy. If one was to look back at our history they will see that abstraction has been used in various forms throughout our past. When I was growing up I do not know how many times I heard politicians say “Leave no child left behind” or “No child left behind” as a major part of their campaign rhetoric in regards to a stance on education. As you can see their slogan is a perfect example of abstraction because it only offers a very general concept about improving our education system but they do not mention how they would like to do it. If they did then they would be adding concrete details to their abstraction thus turning it in to an actual working plan as to how we as a society can help children succeed in school and in life, but then they would not be using abstraction. By now I sure you are thinking what does abstraction have to do with software architecture. You are valid in thinking this way, but abstraction is a wonderful tool used in information technology especially in the world of software architecture. Abstraction is one method of extracting the concepts of an idea so that it can be understood and discussed by others of varying technical abilities and backgrounds. One ways in which I tend to extract my architectural design thoughts is through the use of basic diagrams to convey an idea for a system or a new feature for an existing application. This allows me to generically model an architectural design through the use of views and Unified Markup Language (UML). UML is a standard method for creating a 4+1 Architectural View Models. The 4+1 Architectural View Model consists of 4 views typically created with UML as well as a general description of the concept that is being expressed by a model. The 4+1 Architectural View Model: Logical View: Models a system’s end-user functionality. Development View: Models a system as a collection of components and connectors to illustrate how it is intended to be developed.  Process View: Models the interaction between system components and connectors as to indicate the activities of a system. Physical View: Models the placement of the collection of components and connectors of a system within a physical environment. Recently I had to use the concept of abstraction to express an idea for implementing a new security framework on an existing website. My concept would add session based management in order to properly secure and allow page access based on valid user credentials and last user activity.  I created a basic Process View by using UML diagrams to communicate the basic process flow of my changes in the application so that all of the projects stakeholders would be able to understand my idea. Additionally I created a Logical View on a whiteboard while conveying the process workflow with a few stakeholders to show how end-user will be affected by the new framework and gaining additional input about the design. After my Logical and Process Views were accepted I then started on creating a more detailed Development View in order to map how the system will be built based on the concept of components and connections based on the previously defined interactions. I really did not need to create a Physical view for this idea because we were updating an existing system that was already deployed based on an existing Physical View. What do you think about the use of abstraction in the development of software architecture? Please let me know.

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  • Octree subdivision problem

    - by ChaosDev
    Im creating octree manually and want function for effectively divide all nodes and their subnodes - For example - I press button and subnodes divided - press again - all subnodes divided again. Must be like - 1 - 8 - 64. The problem is - i dont understand how organize recursive loops for that. OctreeNode in my unoptimized implementation contain pointers to subnodes(childs),parent,extra vector(contains dublicates of child),generation info and lots of information for drawing. class gOctreeNode { //necessary fields gOctreeNode* FrontBottomLeftNode; gOctreeNode* FrontBottomRightNode; gOctreeNode* FrontTopLeftNode; gOctreeNode* FrontTopRightNode; gOctreeNode* BackBottomLeftNode; gOctreeNode* BackBottomRightNode; gOctreeNode* BackTopLeftNode; gOctreeNode* BackTopRightNode; gOctreeNode* mParentNode; std::vector<gOctreeNode*> m_ChildsVector; UINT mGeneration; bool mSplitted; bool isSplitted(){return m_Splitted;} .... //unnecessary fields }; DivideNode of Octree class fill these fields, set mSplitted to true, and prepare for correctly drawing. Octree contains basic nodes(m_nodes). Basic node can be divided, but now I want recursivly divide already divided basic node with 8 subnodes. So I write this function. void DivideAllChildCells(int ix,int ih,int id) { std::vector<gOctreeNode*> nlist; std::vector<gOctreeNode*> dlist; int index = (ix * m_Height * m_Depth) + (ih * m_Depth) + (id * 1);//get index of specified node gOctreeNode* baseNode = m_nodes[index].get(); nlist.push_back(baseNode->FrontTopLeftNode); nlist.push_back(baseNode->FrontTopRightNode); nlist.push_back(baseNode->FrontBottomLeftNode); nlist.push_back(baseNode->FrontBottomRightNode); nlist.push_back(baseNode->BackBottomLeftNode); nlist.push_back(baseNode->BackBottomRightNode); nlist.push_back(baseNode->BackTopLeftNode); nlist.push_back(baseNode->BackTopRightNode); bool cont = true; UINT d = 0;//additional recursive loop param (?) UINT g = 0;//additional recursive loop param (?) LoopNodes(d,g,nlist,dlist); //Divide resulting nodes for(UINT i = 0; i < dlist.size(); i++) { DivideNode(dlist[i]); } } And now, back to the main question,I present LoopNodes, which must do all work for giving dlist nodes for splitting. void LoopNodes(UINT& od,UINT& og,std::vector<gOctreeNode*>& nlist,std::vector<gOctreeNode*>& dnodes) { //od++;//recursion depth bool f = false; //pass through childs for(UINT i = 0; i < 8; i++) { if(nlist[i]->isSplitted())//if node splitted and have childs { //pass forward through tree for(UINT j = 0; j < 8; j++) { nlist[j] = nlist[j]->m_ChildsVector[j];//set pointers to these childs } LoopNodes(od,og,nlist,dnodes); } else //if no childs { //add to split vector dnodes.push_back(nlist[i]); } } } This version of loop nodes works correctly for 2(or 1?) generations after - this will not divide neightbours nodes, only some corners. I need correct algorithm. Screenshot All I need - is correct version of LoopNodes, which can add all nodes for DivideNode.

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  • I thought the new AUTO_SAMPLE_SIZE in Oracle Database 11g looked at all the rows in a table so why do I see a very small sample size on some tables?

    - by Maria Colgan
    I recently got asked this question and thought it was worth a quick blog post to explain in a little more detail what is going on with the new AUTO_SAMPLE_SIZE in Oracle Database 11g and what you should expect to see in the dictionary views. Let’s take the SH.CUSTOMERS table as an example.  There are 55,500 rows in the SH.CUSTOMERS tables. If we gather statistics on the SH.CUSTOMERS using the new AUTO_SAMPLE_SIZE but without collecting histogram we can check what sample size was used by looking in the USER_TABLES and USER_TAB_COL_STATISTICS dictionary views. The sample sized shown in the USER_TABLES is 55,500 rows or the entire table as expected. In USER_TAB_COL_STATISTICS most columns show 55,500 rows as the sample size except for four columns (CUST_SRC_ID, CUST_EFF_TO, CUST_MARTIAL_STATUS, CUST_INCOME_LEVEL ). The CUST_SRC_ID and CUST_EFF_TO columns have no sample size listed because there are only NULL values in these columns and the statistics gathering procedure skips NULL values. The CUST_MARTIAL_STATUS (38,072) and the CUST_INCOME_LEVEL (55,459) columns show less than 55,500 rows as their sample size because of the presence of NULL values in these columns. In the SH.CUSTOMERS table 17,428 rows have a NULL as the value for CUST_MARTIAL_STATUS column (17428+38072 = 55500), while 41 rows have a NULL values for the CUST_INCOME_LEVEL column (41+55459 = 55500). So we can confirm that the new AUTO_SAMPLE_SIZE algorithm will use all non-NULL values when gathering basic table and column level statistics. Now we have clear understanding of what sample size to expect lets include histogram creation as part of the statistics gathering. Again we can look in the USER_TABLES and USER_TAB_COL_STATISTICS dictionary views to find the sample size used. The sample size seen in USER_TABLES is 55,500 rows but if we look at the column statistics we see that it is same as in previous case except  for columns  CUST_POSTAL_CODE and  CUST_CITY_ID. You will also notice that these columns now have histograms created on them. The sample size shown for these columns is not the sample size used to gather the basic column statistics. AUTO_SAMPLE_SIZE still uses all the rows in the table - the NULL rows to gather the basic column statistics (55,500 rows in this case). The size shown is the sample size used to create the histogram on the column. When we create a histogram we try to build it on a sample that has approximately 5,500 non-null values for the column.  Typically all of the histograms required for a table are built from the same sample. In our example the histograms created on CUST_POSTAL_CODE and the CUST_CITY_ID were built on a single sample of ~5,500 (5,450 rows) as these columns contained only non-null values. However, if one or more of the columns that requires a histogram has null values then the sample size maybe increased in order to achieve a sample of 5,500 non-null values for those columns. n addition, if the difference between the number of nulls in the columns varies greatly, we may create multiple samples, one for the columns that have a low number of null values and one for the columns with a high number of null values.  This scheme enables us to get close to 5,500 non-null values for each column. +Maria Colgan

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  • Integrating JavaScript Unit Tests with Visual Studio

    - by Stephen Walther
    Modern ASP.NET web applications take full advantage of client-side JavaScript to provide better interactivity and responsiveness. If you are building an ASP.NET application in the right way, you quickly end up with lots and lots of JavaScript code. When writing server code, you should be writing unit tests. One big advantage of unit tests is that they provide you with a safety net that enable you to safely modify your existing code – for example, fix bugs, add new features, and make performance enhancements -- without breaking your existing code. Every time you modify your code, you can execute your unit tests to verify that you have not broken anything. For the same reason that you should write unit tests for your server code, you should write unit tests for your client code. JavaScript is just as susceptible to bugs as C#. There is no shortage of unit testing frameworks for JavaScript. Each of the major JavaScript libraries has its own unit testing framework. For example, jQuery has QUnit, Prototype has UnitTestJS, YUI has YUI Test, and Dojo has Dojo Objective Harness (DOH). The challenge is integrating a JavaScript unit testing framework with Visual Studio. Visual Studio and Visual Studio ALM provide fantastic support for server-side unit tests. You can easily view the results of running your unit tests in the Visual Studio Test Results window. You can set up a check-in policy which requires that all unit tests pass before your source code can be committed to the source code repository. In addition, you can set up Team Build to execute your unit tests automatically. Unfortunately, Visual Studio does not provide “out-of-the-box” support for JavaScript unit tests. MS Test, the unit testing framework included in Visual Studio, does not support JavaScript unit tests. As soon as you leave the server world, you are left on your own. The goal of this blog entry is to describe one approach to integrating JavaScript unit tests with MS Test so that you can execute your JavaScript unit tests side-by-side with your C# unit tests. The goal is to enable you to execute JavaScript unit tests in exactly the same way as server-side unit tests. You can download the source code described by this project by scrolling to the end of this blog entry. Rejected Approach: Browser Launchers One popular approach to executing JavaScript unit tests is to use a browser as a test-driver. When you use a browser as a test-driver, you open up a browser window to execute and view the results of executing your JavaScript unit tests. For example, QUnit – the unit testing framework for jQuery – takes this approach. The following HTML page illustrates how you can use QUnit to create a unit test for a function named addNumbers(). <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title>Using QUnit</title> <link rel="stylesheet" href="http://github.com/jquery/qunit/raw/master/qunit/qunit.css" type="text/css" /> </head> <body> <h1 id="qunit-header">QUnit example</h1> <h2 id="qunit-banner"></h2> <div id="qunit-testrunner-toolbar"></div> <h2 id="qunit-userAgent"></h2> <ol id="qunit-tests"></ol> <div id="qunit-fixture">test markup, will be hidden</div> <script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script> <script type="text/javascript" src="http://github.com/jquery/qunit/raw/master/qunit/qunit.js"></script> <script type="text/javascript"> // The function to test function addNumbers(a, b) { return a+b; } // The unit test test("Test of addNumbers", function () { equals(4, addNumbers(1,3), "1+3 should be 4"); }); </script> </body> </html> This test verifies that calling addNumbers(1,3) returns the expected value 4. When you open this page in a browser, you can see that this test does, in fact, pass. The idea is that you can quickly refresh this QUnit HTML JavaScript test driver page in your browser whenever you modify your JavaScript code. In other words, you can keep a browser window open and keep refreshing it over and over while you are developing your application. That way, you can know very quickly whenever you have broken your JavaScript code. While easy to setup, there are several big disadvantages to this approach to executing JavaScript unit tests: You must view your JavaScript unit test results in a different location than your server unit test results. The JavaScript unit test results appear in the browser and the server unit test results appear in the Visual Studio Test Results window. Because all of your unit test results don’t appear in a single location, you are more likely to introduce bugs into your code without noticing it. Because your unit tests are not integrated with Visual Studio – in particular, MS Test -- you cannot easily include your JavaScript unit tests when setting up check-in policies or when performing automated builds with Team Build. A more sophisticated approach to using a browser as a test-driver is to automate the web browser. Instead of launching the browser and loading the test code yourself, you use a framework to automate this process. There are several different testing frameworks that support this approach: · Selenium – Selenium is a very powerful framework for automating browser tests. You can create your tests by recording a Firefox session or by writing the test driver code in server code such as C#. You can learn more about Selenium at http://seleniumhq.org/. LTAF – The ASP.NET team uses the Lightweight Test Automation Framework to test JavaScript code in the ASP.NET framework. You can learn more about LTAF by visiting the project home at CodePlex: http://aspnet.codeplex.com/releases/view/35501 jsTestDriver – This framework uses Java to automate the browser. jsTestDriver creates a server which can be used to automate multiple browsers simultaneously. This project is located at http://code.google.com/p/js-test-driver/ TestSwam – This framework, created by John Resig, uses PHP to automate the browser. Like jsTestDriver, the framework creates a test server. You can open multiple browsers that are automated by the test server. Learn more about TestSwarm by visiting the following address: https://github.com/jeresig/testswarm/wiki Yeti – This is the framework introduced by Yahoo for automating browser tests. Yeti uses server-side JavaScript and depends on Node.js. Learn more about Yeti at http://www.yuiblog.com/blog/2010/08/25/introducing-yeti-the-yui-easy-testing-interface/ All of these frameworks are great for integration tests – however, they are not the best frameworks to use for unit tests. In one way or another, all of these frameworks depend on executing tests within the context of a “living and breathing” browser. If you create an ASP.NET Unit Test then Visual Studio will launch a web server before executing the unit test. Why is launching a web server so bad? It is not the worst thing in the world. However, it does introduce dependencies that prevent your code from being tested in isolation. One of the defining features of a unit test -- versus an integration test – is that a unit test tests code in isolation. Another problem with launching a web server when performing unit tests is that launching a web server can be slow. If you cannot execute your unit tests quickly, you are less likely to execute your unit tests each and every time you make a code change. You are much more likely to fall into the pit of failure. Launching a browser when performing a JavaScript unit test has all of the same disadvantages as launching a web server when performing an ASP.NET unit test. Instead of testing a unit of JavaScript code in isolation, you are testing JavaScript code within the context of a particular browser. Using the frameworks listed above for integration tests makes perfect sense. However, I want to consider a different approach for creating unit tests for JavaScript code. Using Server-Side JavaScript for JavaScript Unit Tests A completely different approach to executing JavaScript unit tests is to perform the tests outside of any browser. If you really want to test JavaScript then you should test JavaScript and leave the browser out of the testing process. There are several ways that you can execute JavaScript on the server outside the context of any browser: Rhino – Rhino is an implementation of JavaScript written in Java. The Rhino project is maintained by the Mozilla project. Learn more about Rhino at http://www.mozilla.org/rhino/ V8 – V8 is the open-source Google JavaScript engine written in C++. This is the JavaScript engine used by the Chrome web browser. You can download V8 and embed it in your project by visiting http://code.google.com/p/v8/ JScript – JScript is the JavaScript Script Engine used by Internet Explorer (up to but not including Internet Explorer 9), Windows Script Host, and Active Server Pages. Internet Explorer is still the most popular web browser. Therefore, I decided to focus on using the JScript Script Engine to execute JavaScript unit tests. Using the Microsoft Script Control There are two basic ways that you can pass JavaScript to the JScript Script Engine and execute the code: use the Microsoft Windows Script Interfaces or use the Microsoft Script Control. The difficult and proper way to execute JavaScript using the JScript Script Engine is to use the Microsoft Windows Script Interfaces. You can learn more about the Script Interfaces by visiting http://msdn.microsoft.com/en-us/library/t9d4xf28(VS.85).aspx The main disadvantage of using the Script Interfaces is that they are difficult to use from .NET. There is a great series of articles on using the Script Interfaces from C# located at http://www.drdobbs.com/184406028. I picked the easier alternative and used the Microsoft Script Control. The Microsoft Script Control is an ActiveX control that provides a higher level abstraction over the Window Script Interfaces. You can download the Microsoft Script Control from here: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=d7e31492-2595-49e6-8c02-1426fec693ac After you download the Microsoft Script Control, you need to add a reference to it to your project. Select the Visual Studio menu option Project, Add Reference to open the Add Reference dialog. Select the COM tab and add the Microsoft Script Control 1.0. Using the Script Control is easy. You call the Script Control AddCode() method to add JavaScript code to the Script Engine. Next, you call the Script Control Run() method to run a particular JavaScript function. The reference documentation for the Microsoft Script Control is located at the MSDN website: http://msdn.microsoft.com/en-us/library/aa227633%28v=vs.60%29.aspx Creating the JavaScript Code to Test To keep things simple, let’s imagine that you want to test the following JavaScript function named addNumbers() which simply adds two numbers together: MvcApplication1\Scripts\Math.js function addNumbers(a, b) { return 5; } Notice that the addNumbers() method always returns the value 5. Right-now, it will not pass a good unit test. Create this file and save it in your project with the name Math.js in your MVC project’s Scripts folder (Save the file in your actual MVC application and not your MVC test application). Creating the JavaScript Test Helper Class To make it easier to use the Microsoft Script Control in unit tests, we can create a helper class. This class contains two methods: LoadFile() – Loads a JavaScript file. Use this method to load the JavaScript file being tested or the JavaScript file containing the unit tests. ExecuteTest() – Executes the JavaScript code. Use this method to execute a JavaScript unit test. Here’s the code for the JavaScriptTestHelper class: JavaScriptTestHelper.cs   using System; using System.IO; using Microsoft.VisualStudio.TestTools.UnitTesting; using MSScriptControl; namespace MvcApplication1.Tests { public class JavaScriptTestHelper : IDisposable { private ScriptControl _sc; private TestContext _context; /// <summary> /// You need to use this helper with Unit Tests and not /// Basic Unit Tests because you need a Test Context /// </summary> /// <param name="testContext">Unit Test Test Context</param> public JavaScriptTestHelper(TestContext testContext) { if (testContext == null) { throw new ArgumentNullException("TestContext"); } _context = testContext; _sc = new ScriptControl(); _sc.Language = "JScript"; _sc.AllowUI = false; } /// <summary> /// Load the contents of a JavaScript file into the /// Script Engine. /// </summary> /// <param name="path">Path to JavaScript file</param> public void LoadFile(string path) { var fileContents = File.ReadAllText(path); _sc.AddCode(fileContents); } /// <summary> /// Pass the path of the test that you want to execute. /// </summary> /// <param name="testMethodName">JavaScript function name</param> public void ExecuteTest(string testMethodName) { dynamic result = null; try { result = _sc.Run(testMethodName, new object[] { }); } catch { var error = ((IScriptControl)_sc).Error; if (error != null) { var description = error.Description; var line = error.Line; var column = error.Column; var text = error.Text; var source = error.Source; if (_context != null) { var details = String.Format("{0} \r\nLine: {1} Column: {2}", source, line, column); _context.WriteLine(details); } } throw new AssertFailedException(error.Description); } } public void Dispose() { _sc = null; } } }     Notice that the JavaScriptTestHelper class requires a Test Context to be instantiated. For this reason, you can use the JavaScriptTestHelper only with a Visual Studio Unit Test and not a Basic Unit Test (These are two different types of Visual Studio project items). Add the JavaScriptTestHelper file to your MVC test application (for example, MvcApplication1.Tests). Creating the JavaScript Unit Test Next, we need to create the JavaScript unit test function that we will use to test the addNumbers() function. Create a folder in your MVC test project named JavaScriptTests and add the following JavaScript file to this folder: MvcApplication1.Tests\JavaScriptTests\MathTest.js /// <reference path="JavaScriptUnitTestFramework.js"/> function testAddNumbers() { // Act var result = addNumbers(1, 3); // Assert assert.areEqual(4, result, "addNumbers did not return right value!"); }   The testAddNumbers() function takes advantage of another JavaScript library named JavaScriptUnitTestFramework.js. This library contains all of the code necessary to make assertions. Add the following JavaScriptnitTestFramework.js to the same folder as the MathTest.js file: MvcApplication1.Tests\JavaScriptTests\JavaScriptUnitTestFramework.js var assert = { areEqual: function (expected, actual, message) { if (expected !== actual) { throw new Error("Expected value " + expected + " is not equal to " + actual + ". " + message); } } }; There is only one type of assertion supported by this file: the areEqual() assertion. Most likely, you would want to add additional types of assertions to this file to make it easier to write your JavaScript unit tests. Deploying the JavaScript Test Files This step is non-intuitive. When you use Visual Studio to run unit tests, Visual Studio creates a new folder and executes a copy of the files in your project. After you run your unit tests, your Visual Studio Solution will contain a new folder named TestResults that includes a subfolder for each test run. You need to configure Visual Studio to deploy your JavaScript files to the test run folder or Visual Studio won’t be able to find your JavaScript files when you execute your unit tests. You will get an error that looks something like this when you attempt to execute your unit tests: You can configure Visual Studio to deploy your JavaScript files by adding a Test Settings file to your Visual Studio Solution. It is important to understand that you need to add this file to your Visual Studio Solution and not a particular Visual Studio project. Right-click your Solution in the Solution Explorer window and select the menu option Add, New Item. Select the Test Settings item and click the Add button. After you create a Test Settings file for your solution, you can indicate that you want a particular folder to be deployed whenever you perform a test run. Select the menu option Test, Edit Test Settings to edit your test configuration file. Select the Deployment tab and select your MVC test project’s JavaScriptTest folder to deploy. Click the Apply button and the Close button to save the changes and close the dialog. Creating the Visual Studio Unit Test The very last step is to create the Visual Studio unit test (the MS Test unit test). Add a new unit test to your MVC test project by selecting the menu option Add New Item and selecting the Unit Test project item (Do not select the Basic Unit Test project item): The difference between a Basic Unit Test and a Unit Test is that a Unit Test includes a Test Context. We need this Test Context to use the JavaScriptTestHelper class that we created earlier. Enter the following test method for the new unit test: [TestMethod] public void TestAddNumbers() { var jsHelper = new JavaScriptTestHelper(this.TestContext); // Load JavaScript files jsHelper.LoadFile("JavaScriptUnitTestFramework.js"); jsHelper.LoadFile(@"..\..\..\MvcApplication1\Scripts\Math.js"); jsHelper.LoadFile("MathTest.js"); // Execute JavaScript Test jsHelper.ExecuteTest("testAddNumbers"); } This code uses the JavaScriptTestHelper to load three files: JavaScripUnitTestFramework.js – Contains the assert functions. Math.js – Contains the addNumbers() function from your MVC application which is being tested. MathTest.js – Contains the JavaScript unit test function. Next, the test method calls the JavaScriptTestHelper ExecuteTest() method to execute the testAddNumbers() JavaScript function. Running the Visual Studio JavaScript Unit Test After you complete all of the steps described above, you can execute the JavaScript unit test just like any other unit test. You can use the keyboard combination CTRL-R, CTRL-A to run all of the tests in the current Visual Studio Solution. Alternatively, you can use the buttons in the Visual Studio toolbar to run the tests: (Unfortunately, the Run All Impacted Tests button won’t work correctly because Visual Studio won’t detect that your JavaScript code has changed. Therefore, you should use either the Run Tests in Current Context or Run All Tests in Solution options instead.) The results of running the JavaScript tests appear side-by-side with the results of running the server tests in the Test Results window. For example, if you Run All Tests in Solution then you will get the following results: Notice that the TestAddNumbers() JavaScript test has failed. That is good because our addNumbers() function is hard-coded to always return the value 5. If you double-click the failing JavaScript test, you can view additional details such as the JavaScript error message and the line number of the JavaScript code that failed: Summary The goal of this blog entry was to explain an approach to creating JavaScript unit tests that can be easily integrated with Visual Studio and Visual Studio ALM. I described how you can use the Microsoft Script Control to execute JavaScript on the server. By taking advantage of the Microsoft Script Control, we were able to execute our JavaScript unit tests side-by-side with all of our other unit tests and view the results in the standard Visual Studio Test Results window. You can download the code discussed in this blog entry from here: http://StephenWalther.com/downloads/Blog/JavaScriptUnitTesting/JavaScriptUnitTests.zip Before running this code, you need to first install the Microsoft Script Control which you can download from here: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=d7e31492-2595-49e6-8c02-1426fec693ac

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  • Microsoft Introduces WebMatrix

    - by Rick Strahl
    originally published in CoDe Magazine Editorial Microsoft recently released the first CTP of a new development environment called WebMatrix, which along with some of its supporting technologies are squarely aimed at making the Microsoft Web Platform more approachable for first-time developers and hobbyists. But in the process, it also provides some updated technologies that can make life easier for existing .NET developers. Let’s face it: ASP.NET development isn’t exactly trivial unless you already have a fair bit of familiarity with sophisticated development practices. Stick a non-developer in front of Visual Studio .NET or even the Visual Web Developer Express edition and it’s not likely that the person in front of the screen will be very productive or feel inspired. Yet other technologies like PHP and even classic ASP did provide the ability for non-developers and hobbyists to become reasonably proficient in creating basic web content quickly and efficiently. WebMatrix appears to be Microsoft’s attempt to bring back some of that simplicity with a number of technologies and tools. The key is to provide a friendly and fully self-contained development environment that provides all the tools needed to build an application in one place, as well as tools that allow publishing of content and databases easily to the web server. WebMatrix is made up of several components and technologies: IIS Developer Express IIS Developer Express is a new, self-contained development web server that is fully compatible with IIS 7.5 and based on the same codebase that IIS 7.5 uses. This new development server replaces the much less compatible Cassini web server that’s been used in Visual Studio and the Express editions. IIS Express addresses a few shortcomings of the Cassini server such as the inability to serve custom ISAPI extensions (i.e., things like PHP or ASP classic for example), as well as not supporting advanced authentication. IIS Developer Express provides most of the IIS 7.5 feature set providing much better compatibility between development and live deployment scenarios. SQL Server Compact 4.0 Database access is a key component for most web-driven applications, but on the Microsoft stack this has mostly meant you have to use SQL Server or SQL Server Express. SQL Server Compact is not new-it’s been around for a few years, but it’s been severely hobbled in the past by terrible tool support and the inability to support more than a single connection in Microsoft’s attempt to avoid losing SQL Server licensing. The new release of SQL Server Compact 4.0 supports multiple connections and you can run it in ASP.NET web applications simply by installing an assembly into the bin folder of the web application. In effect, you don’t have to install a special system configuration to run SQL Compact as it is a drop-in database engine: Copy the small assembly into your BIN folder (or from the GAC if installed fully), create a connection string against a local file-based database file, and then start firing SQL requests. Additionally WebMatrix includes nice tools to edit the database tables and files, along with tools to easily upsize (and hopefully downsize in the future) to full SQL Server. This is a big win, pending compatibility and performance limits. In my simple testing the data engine performed well enough for small data sets. This is not only useful for web applications, but also for desktop applications for which a fully installed SQL engine like SQL Server would be overkill. Having a local data store in those applications that can potentially be accessed by multiple users is a welcome feature. ASP.NET Razor View Engine What? Yet another native ASP.NET view engine? We already have Web Forms and various different flavors of using that view engine with Web Forms and MVC. Do we really need another? Microsoft thinks so, and Razor is an implementation of a lightweight, script-only view engine. Unlike the Web Forms view engine, Razor works only with inline code, snippets, and markup; therefore, it is more in line with current thinking of what a view engine should represent. There’s no support for a “page model” or any of the other Web Forms features of the full-page framework, but just a lightweight scripting engine that works with plain markup plus embedded expressions and code. The markup syntax for Razor is geared for minimal typing, plus some progressive detection of where a script block/expression starts and ends. This results in a much leaner syntax than the typical ASP.NET Web Forms alligator (<% %>) tags. Razor uses the @ sign plus standard C# (or Visual Basic) block syntax to delineate code snippets and expressions. Here’s a very simple example of what Razor markup looks like along with some comment annotations: <!DOCTYPE html> <html>     <head>         <title></title>     </head>     <body>     <h1>Razor Test</h1>          <!-- simple expressions -->     @DateTime.Now     <hr />     <!-- method expressions -->     @DateTime.Now.ToString("T")          <!-- code blocks -->     @{         List<string> names = new List<string>();         names.Add("Rick");         names.Add("Markus");         names.Add("Claudio");         names.Add("Kevin");     }          <!-- structured block statements -->     <ul>     @foreach(string name in names){             <li>@name</li>     }     </ul>           <!-- Conditional code -->        @if(true) {                        <!-- Literal Text embedding in code -->        <text>         true        </text>;    }    else    {        <!-- Literal Text embedding in code -->       <text>       false       </text>;    }    </body> </html> Like the Web Forms view engine, Razor parses pages into code, and then executes that run-time compiled code. Effectively a “page” becomes a code file with markup becoming literal text written into the Response stream, code snippets becoming raw code, and expressions being written out with Response.Write(). The code generated from Razor doesn’t look much different from similar Web Forms code that only uses script tags; so although the syntax may look different, the operational model is fairly similar to the Web Forms engine minus the overhead of the large Page object model. However, there are differences: -Razor pages are based on a new base class, Microsoft.WebPages.WebPage, which is hosted in the Microsoft.WebPages assembly that houses all the Razor engine parsing and processing logic. Browsing through the assembly (in the generated ASP.NET Temporary Files folder or GAC) will give you a good idea of the functionality that Razor provides. If you look closely, a lot of the feature set matches ASP.NET MVC’s view implementation as well as many of the helper classes found in MVC. It’s not hard to guess the motivation for this sort of view engine: For beginning developers the simple markup syntax is easier to work with, although you obviously still need to have some understanding of the .NET Framework in order to create dynamic content. The syntax is easier to read and grok and much shorter to type than ASP.NET alligator tags (<% %>) and also easier to understand aesthetically what’s happening in the markup code. Razor also is a better fit for Microsoft’s vision of ASP.NET MVC: It’s a new view engine without the baggage of Web Forms attached to it. The engine is more lightweight since it doesn’t carry all the features and object model of Web Forms with it and it can be instantiated directly outside of the HTTP environment, which has been rather tricky to do for the Web Forms view engine. Having a standalone script parser is a huge win for other applications as well – it makes it much easier to create script or meta driven output generators for many types of applications from code/screen generators, to simple form letters to data merging applications with user customizability. For me personally this is very useful side effect and who knows maybe Microsoft will actually standardize they’re scripting engines (die T4 die!) on this engine. Razor also better fits the “view-based” approach where the view is supposed to be mostly a visual representation that doesn’t hold much, if any, code. While you can still use code, the code you do write has to be self-contained. Overall I wouldn’t be surprised if Razor will become the new standard view engine for MVC in the future – and in fact there have been announcements recently that Razor will become the default script engine in ASP.NET MVC 3.0. Razor can also be used in existing Web Forms and MVC applications, although that’s not working currently unless you manually configure the script mappings and add the appropriate assemblies. It’s possible to do it, but it’s probably better to wait until Microsoft releases official support for Razor scripts in Visual Studio. Once that happens, you can simply drop .cshtml and .vbhtml pages into an existing ASP.NET project and they will work side by side with classic ASP.NET pages. WebMatrix Development Environment To tie all of these three technologies together, Microsoft is shipping WebMatrix with an integrated development environment. An integrated gallery manager makes it easy to download and load existing projects, and then extend them with custom functionality. It seems to be a prominent goal to provide community-oriented content that can act as a starting point, be it via a custom templates or a complete standard application. The IDE includes a project manager that works with a single project and provides an integrated IDE/editor for editing the .cshtml and .vbhtml pages. A run button allows you to quickly run pages in the project manager in a variety of browsers. There’s no debugging support for code at this time. Note that Razor pages don’t require explicit compilation, so making a change, saving, and then refreshing your page in the browser is all that’s needed to see changes while testing an application locally. It’s essentially using the auto-compiling Web Project that was introduced with .NET 2.0. All code is compiled during run time into dynamically created assemblies in the ASP.NET temp folder. WebMatrix also has PHP Editing support with syntax highlighting. You can load various PHP-based applications from the WebMatrix Web Gallery directly into the IDE. Most of the Web Gallery applications are ready to install and run without further configuration, with Wizards taking you through installation of tools, dependencies, and configuration of the database as needed. WebMatrix leverages the Web Platform installer to pull the pieces down from websites in a tight integration of tools that worked nicely for the four or five applications I tried this out on. Click a couple of check boxes and fill in a few simple configuration options and you end up with a running application that’s ready to be customized. Nice! You can easily deploy completed applications via WebDeploy (to an IIS server) or FTP directly from within the development environment. The deploy tool also can handle automatically uploading and installing the database and all related assemblies required, making deployment a simple one-click install step. Simplified Database Access The IDE contains a database editor that can edit SQL Compact and SQL Server databases. There is also a Database helper class that facilitates database access by providing easy-to-use, high-level query execution and iteration methods: @{       var db = Database.OpenFile("FirstApp.sdf");     string sql = "select * from customers where Id > @0"; } <ul> @foreach(var row in db.Query(sql,1)){         <li>@row.FirstName @row.LastName</li> } </ul> The query function takes a SQL statement plus any number of positional (@0,@1 etc.) SQL parameters by simple values. The result is returned as a collection of rows which in turn have a row object with dynamic properties for each of the columns giving easy (though untyped) access to each of the fields. Likewise Execute and ExecuteNonQuery allow execution of more complex queries using similar parameter passing schemes. Note these queries use string-based queries rather than LINQ or Entity Framework’s strongly typed LINQ queries. While this may seem like a step back, it’s also in line with the expectations of non .NET script developers who are quite used to writing and using SQL strings in code rather than using OR/M frameworks. The only question is why was something not included from the beginning in .NET and Microsoft made developers build custom implementations of these basic building blocks. The implementation looks a lot like a DataTable-style data access mechanism, but to be fair, this is a common approach in scripting languages. This type of syntax that uses simple, static, data object methods to perform simple data tasks with one line of code are common in scripting languages and are a good match for folks working in PHP/Python, etc. Seems like Microsoft has taken great advantage of .NET 4.0’s dynamic typing to provide this sort of interface for row iteration where each row has properties for each field. FWIW, all the examples demonstrate using local SQL Compact files - I was unable to get a SQL Server connection string to work with the Database class (the connection string wasn’t accepted). However, since the code in the page is still plain old .NET, you can easily use standard ADO.NET code or even LINQ or Entity Framework models that are created outside of WebMatrix in separate assemblies as required. The good the bad the obnoxious - It’s still .NET The beauty (or curse depending on how you look at it :)) of Razor and the compilation model is that, behind it all, it’s still .NET. Although the syntax may look foreign, it’s still all .NET behind the scenes. You can easily access existing tools, helpers, and utilities simply by adding them to the project as references or to the bin folder. Razor automatically recognizes any assembly reference from assemblies in the bin folder. In the default configuration, Microsoft provides a host of helper functions in a Microsoft.WebPages assembly (check it out in the ASP.NET temp folder for your application), which includes a host of HTML Helpers. If you’ve used ASP.NET MVC before, a lot of the helpers should look familiar. Documentation at the moment is sketchy-there’s a very rough API reference you can check out here: http://www.asp.net/webmatrix/tutorials/asp-net-web-pages-api-reference Who needs WebMatrix? Uhm… good Question Clearly Microsoft is trying hard to create an environment with WebMatrix that is easy to use for newbie developers. The goal seems to be simplicity in providing a minimal development environment and an easy-to-use script engine/language that makes it easy to get started with. There’s also some focus on community features that can be used as starting points, such as Web Gallery applications and templates. The community features in particular are very nice and something that would be nice to eventually see in Visual Studio as well. The question is whether this is too little too late. Developers who have been clamoring for a simpler development environment on the .NET stack have mostly left for other simpler platforms like PHP or Python which are catering to the down and dirty developer. Microsoft will be hard pressed to win those folks-and other hardcore PHP developers-back. Regardless of how much you dress up a script engine fronted by the .NET Framework, it’s still the .NET Framework and all the complexity that drives it. While .NET is a fine solution in its breadth and features once you get a basic handle on the core features, the bar of entry to being productive with the .NET Framework is still pretty high. The MVC style helpers Microsoft provides are a good step in the right direction, but I suspect it’s not enough to shield new developers from having to delve much deeper into the Framework to get even basic applications built. Razor and its helpers is trying to make .NET more accessible but the reality is that in order to do useful stuff that goes beyond the handful of simple helpers you still are going to have to write some C# or VB or other .NET code. If the target is a hobby/amateur/non-programmer the learning curve isn’t made any easier by WebMatrix it’s just been shifted a tad bit further along in your development endeavor when you run out of canned components that are supplied either by Microsoft or the community. The database helpers are interesting and actually I’ve heard a lot of discussion from various developers who’ve been resisting .NET for a really long time perking up at the prospect of easier data access in .NET than the ridiculous amount of code it takes to do even simple data access with raw ADO.NET. It seems sad that such a simple concept and implementation should trigger this sort of response (especially since it’s practically trivial to create helpers like these or pick them up from countless libraries available), but there it is. It also shows that there are plenty of developers out there who are more interested in ‘getting stuff done’ easily than necessarily following the latest and greatest practices which are overkill for many development scenarios. Sometimes it seems that all of .NET is focused on the big life changing issues of development, rather than the bread and butter scenarios that many developers are interested in to get their work accomplished. And that in the end may be WebMatrix’s main raison d'être: To bring some focus back at Microsoft that simpler and more high level solutions are actually needed to appeal to the non-high end developers as well as providing the necessary tools for the high end developers who want to follow the latest and greatest trends. The current version of WebMatrix hits many sweet spots, but it also feels like it has a long way to go before it really can be a tool that a beginning developer or an accomplished developer can feel comfortable with. Although there are some really good ideas in the environment (like the gallery for downloading apps and components) which would be a great addition for Visual Studio as well, the rest of the development environment just feels like crippleware with required functionality missing especially debugging and Intellisense, but also general editor support. It’s not clear whether these are because the product is still in an early alpha release or whether it’s simply designed that way to be a really limited development environment. While simple can be good, nobody wants to feel left out when it comes to necessary tool support and WebMatrix just has that left out feeling to it. If anything WebMatrix’s technology pieces (which are really independent of the WebMatrix product) are what are interesting to developers in general. The compact IIS implementation is a nice improvement for development scenarios and SQL Compact 4.0 seems to address a lot of concerns that people have had and have complained about for some time with previous SQL Compact implementations. By far the most interesting and useful technology though seems to be the Razor view engine for its light weight implementation and it’s decoupling from the ASP.NET/HTTP pipeline to provide a standalone scripting/view engine that is pluggable. The first winner of this is going to be ASP.NET MVC which can now have a cleaner view model that isn’t inconsistent due to the baggage of non-implemented WebForms features that don’t work in MVC. But I expect that Razor will end up in many other applications as a scripting and code generation engine eventually. Visual Studio integration for Razor is currently missing, but is promised for a later release. The ASP.NET MVC team has already mentioned that Razor will eventually become the default MVC view engine, which will guarantee continued growth and development of this tool along those lines. And the Razor engine and support tools actually inherit many of the features that MVC pioneered, so there’s some synergy flowing both ways between Razor and MVC. As an existing ASP.NET developer who’s already familiar with Visual Studio and ASP.NET development, the WebMatrix IDE doesn’t give you anything that you want. The tools provided are minimal and provide nothing that you can’t get in Visual Studio today, except the minimal Razor syntax highlighting, so there’s little need to take a step back. With Visual Studio integration coming later there’s little reason to look at WebMatrix for tooling. It’s good to see that Microsoft is giving some thought about the ease of use of .NET as a platform For so many years, we’ve been piling on more and more new features without trying to take a step back and see how complicated the development/configuration/deployment process has become. Sometimes it’s good to take a step - or several steps - back and take another look and realize just how far we’ve come. WebMatrix is one of those reminders and one that likely will result in some positive changes on the platform as a whole. © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET   IIS7  

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  • NullPointerException when showing JFileChooser

    - by Geo
    I show a JFileChooser with this snippet: public File getDestination() { JFileChooser chooser = new JFileChooser(); chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY); int option = chooser.showSaveDialog(null); if(option == JFileChooser.APPROVE_OPTION) { return chooser.getSelectedFile().getAbsolutePath(); } return new File("."); } Usually, the first time it's showed, it displays & works correctly. The second time, it will always throw this exception: Exception in thread "Basic L&F File Loading Thread" java.lang.NullPointerException at sun.awt.shell.Win32ShellFolder2.pidlsEqual(Unknown Source) at sun.awt.shell.Win32ShellFolder2.equals(Unknown Source) at sun.awt.shell.Win32ShellFolderManager2.isFileSystemRoot(Unknown Source) at sun.awt.shell.ShellFolder.isFileSystemRoot(Unknown Source) at javax.swing.filechooser.FileSystemView.isFileSystemRoot(Unknown Source) at javax.swing.filechooser.WindowsFileSystemView.isTraversable(Unknown Source) at javax.swing.JFileChooser.isTraversable(Unknown Source) at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run0(Unknown Source) at javax.swing.plaf.basic.BasicDirectoryModel$LoadFilesThread.run(Unknown Source) Java -version says: java version "1.6.0_20" Java(TM) SE Runtime Environment (build 1.6.0_20-b02) Java HotSpot(TM) Client VM (build 16.3-b01, mixed mode, sharing) And the thread I found here says I should downgrade the Java version. Should I follow their advice, or is there something I could have done wrong?

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  • Why a Swing app stops my Java servlet ?

    - by Frank
    I have a Swing runnable app which updates messages, then I have a Java servlet that gets messages from Paypal IPN (Instant Payment Notification), when the servlet starts up, in the init(), I starts the Swing runnable app which opens a desktop window, but 30 minutes later an error in the Swing caused the servlet to stop, how can that happen ? Because the runnable is running on it's own thread, servlet started that thread, why an error in that thread will cause the servlet to stop ? public class License_Manager extends JPanel implements Runnable { License_Manager() { Do_GUI(); ... start(); } public static void main(String[] args) { // Schedule a job for the event-dispatching thread : creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { Create_And_Show_GUI(); } }); } } public class PayPal_Servlet extends HttpServlet { public void init(ServletConfig config) throws ServletException { super.init(config); License_Manager.main(null); } protected void processRequest(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { } } And besides the error don't even have anything to do with my code, it looks like this : Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 17 = 0 at java.util.Vector.elementAt(Vector.java:427) at javax.swing.DefaultListModel.getElementAt(DefaultListModel.java:70) at javax.swing.plaf.basic.BasicListUI.paintCell(BasicListUI.java:191) at javax.swing.plaf.basic.BasicListUI.paintImpl(BasicListUI.java:304) at javax.swing.plaf.basic.BasicListUI.paint(BasicListUI.java:227) at javax.swing.plaf.ComponentUI.update(ComponentUI.java:143) at javax.swing.JComponent.paintComponent(JComponent.java:763) at javax.swing.JComponent.paint(JComponent.java:1029) at javax.swing.JComponent.paintChildren(JComponent.java:864) at javax.swing.JComponent.paint(JComponent.java:1038) at javax.swing.JViewport.paint(JViewport.java:747) at javax.swing.JComponent.paintChildren(JComponent.java:864) at javax.swing.JComponent.paint(JComponent.java:1038) at javax.swing.JComponent.paintToOffscreen(JComponent.java:5124) at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:278) at javax.swing.RepaintManager.paint(RepaintManager.java:1220) at javax.swing.JComponent._paintImmediately(JComponent.java:5072) at javax.swing.JComponent.paintImmediately(JComponent.java:4882) at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:803) at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:714) at javax.swing.RepaintManager.seqPaintDirtyRegions(RepaintManager.java:694) at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(SystemEventQueueUtilities.java:128) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209) at java.awt.EventQueue.dispatchEvent(EventQueue.java:597) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161) at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

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  • Language+IDE for teaching high school students?

    - by daveagp
    I'm investigating languages and IDEs for a project involving teaching high-school students (around grade 11). It will teach basics of programming as an introduction to computer science (e.g., including how numbers/strings/characters are represented, using procedures and arrays, control flow, a little bit of algorithms, only very basic I/O). The non-negotiable requirements for this project are: a free up-to-date cross-platform IDE (Win & Mac incl. 64-bit) with debug a compiler where it's easy to learn from your mistakes together with the IDE, a gentle installation+learning curve So far, the best options I see are the following. Are there others I should know about? I am giving a short explanation with each one to generally show what I am looking for. In order from most to least promising: Pascal + FreePascal IDE (it seems a little buggy but actively developed?) Python + Eclipse + PyDev (good but features are overwhelming/hard to navigate) Groovy + Eclipse ('') Python + IDLE (looks unnatural to do debugging, to me) Pascal + Lazarus (IDE overwhelming, e.g. not obvious how to "start from scratch") Preferably, as a rule of thumb, the language should be direct enough that you don't need to wrap every program in a class, don't need to reference a System object to println, etc. I tried a little bit to see if there is something in JavaScript or (non-Visual) Basic along the lines of what I want, but found nothing so far. I would say that C/C++/C#, Java, Ruby, Lisp, VB do not fit my criteria for languages for this project. To reiterate my questions: are any of those 5 options really awesome or un-awesome? Are there other options which are even MORE awesome? Anything for Basic or JavaScript which meets all of the criteria? Thanks!

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  • apache: cgi links lead to a "you have chosen to open foo.cgi", although scriptalias is set

    - by Xiong Chiamiov
    Following this guide on CentOS 5.2, just getting nagios set up for the first time. The main page shows up just fine, but when I try to view any of the pages that should be generated by a cgi process, firefox prompts me to save the .cgi instead, so apache's obviously not understanding that it needs to run the cgi and get back some html from it. The odd thing is, though, that, as far as I can tell, apache should be running these files as cgi. nagios.conf: # SAMPLE CONFIG SNIPPETS FOR APACHE WEB SERVER # Last Modified: 11-26-2005 # # This file contains examples of entries that need # to be incorporated into your Apache web server # configuration file. Customize the paths, etc. as # needed to fit your system. ScriptAlias /nagios/cgi-bin/ "/usr/lib/nagios/cgi/" # SSLRequireSSL Options +ExecCGI AddHandler cgi-script .cgi AllowOverride None Order allow,deny Allow from all # Order deny,allow # Deny from all # Allow from 127.0.0.1 AuthName "Nagios Access" AuthType Basic AuthUserFile /etc/nagios/htpasswd.users Require valid-user Alias /nagios "/usr/share/nagios/" # SSLRequireSSL DirectoryIndex index.php Options None AllowOverride None Order allow,deny Allow from all # Order deny,allow # Deny from all # Allow from 127.0.0.1 AuthName "Nagios Access" AuthType Basic AuthUserFile /etc/nagios/htpasswd.users Require valid-use Either the ScriptAlias directive or ExecCGI option should be triggering this, but neither of them seems to have any effect. This config file is being parsed by apache, because if I move it out of conf.d, /nagios gives a 404. The .cgi files are indeed in the /nagios/cgi-bin/ directory, so I didn't specify the incorrect directory. Searching seemed to only provide people who had difficulty with permissions, which is not the issue here. This seems to me to be a pretty basic thing, but even with the excellent apache documentation, I'm at a bit of a loss (been using cherokee too much lately :) ).

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  • EJB3 - @Column(insertable="false") question

    - by WhiteTigerK
    Hi All, I'm building a J2SE application with EJB3 and an Oracle Express Edition DB. My problem is like that - I set an EntityBean in my project which matches a table in the DB. The table contains a column which is not nullable and has a default value. All I want is that when persisting a new data to this table using the EJB, the column's value will get its default value. This is how I set it in the project: //holds user's first name @Basic(optional = true) @Column(name = "FIRST_NAME", insertable = false, updatable = true, nullable = false) private String m_firstName; I also set it in the ORM.XML file: <basic name="firstName"> <column name="FIRST_NAME" insertable="false" updatable="true" nullable="false"/> </basic> But for some reason, when creating a new EntityBean and not setting the first name field, and then trying to persist it, i get the following exception: Exception [TOPLINK-4002] (Oracle TopLink Essentials - 2.1 (Build b60e-fcs (12/23/2008))): oracle.toplink.essentials.exceptions.DatabaseException Internal Exception: java.sql.SQLException: ORA-01400: cannot insert NULL into ("TSDB"."USERS"."FIRST_NAME") Which means that the persistence manager tries to insert the first name field although I told it not to. Am I doing something wrong here ? Thanks!

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  • Missing ideas in programming language design

    - by meyka
    I wanted to try something new and so I designed some programming languages and wrote interpreters for them: A rather low-level, not very expressive language. (I didn't want to parse complex expressions right at the beginning) It featured: Variables (yay) Subroutines, with a call stack Basic arithmetic functions, basic string manipulation, ... Code in the language looks like this: set i 0 inc i print i Very, very basic you see. A more high-level language I decided to make it structured and so it featured things like if-else, while, functions, and so on. The stuff most programming languages have. Ended up like a unworthy Python clone, I hated that. A code-golf language Which ended up similar to J, golfcode, APL, etc. Nothing special As you can see: I don't lack the skills but the ideas. I can't figure out anything new, not even bad, unneccessary things, for my languages. - Do you know of some weird things I could implement in my languages, which don't try to make programming harder (like most esoteric languages) but funnier or more different from other languages? It can't be possible that every weird thing has been tried out so far, or?

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