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• The Grenelle II Act In France: A Milestone Towards Integrated Reporting

  - by Evelyn Neumayr

  By Elena Avesani, Principal Product Strategy Manager, Oracle In July of 2010, France took a significant step towards mandating integrated sustainability and financial reporting for all large companies with a new law called Grenelle II. Article 225 of Grenelle II requires that many listed companies on the French stock exchanges incorporate information on the social and environmental consequences of their activities into their annual reports, as well as their societal commitments for sustainable development. The decree that implements Article 225 of Grenelle II was passed in April 2012. Grenelle II is the strongest governmental mandate yet in support of sustainability reporting. The law defines the phase-in process, with large listed companies expected to comply in their 2012 reports and smaller companies expected to comply with their 2014 annual reports. This extra-financial information will have to be embedded in the annual management report, approved by the Board of Directors, verified by a third-party body and given to the annual general meeting. The subjects that must be reported on are grouped into Environmental, Social, and Governance categories. Oracle solutions can help organizations integrate financial and sustainability reporting and provide a more accurate and auditable approach to collecting, consolidating, and reporting such environmental, social, and economic metrics. Through Oracle Environmental Accounting and Reporting and Oracle Hyperion Financial Management Sustainability Starter Kit organizations can collect environmental, social and governance data and collect and consolidate corporate sustainability reporting data from multiple systems and business units. For more information about these solutions please contact [email protected].

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• Storing SCA Metadata in the Oracle Metadata Services Repository by Nicolás Fonnegra Martinez and Markus Lohn

  - by JuergenKress

  The advantages of using the Oracle Metadata Services Repository as a central storage for the metadata. SCA has been available since the release of the Oracle SOA Suite 11g. This technology combines and orchestrates several SOA components inside an SCA composite, making design, development, deployment, and maintenance easier. SCA development is metadata-driven, meaning that metadata artifacts, such as Web Services Description Language (WSDL), XML Schema Definition (XSD), XML, others, define the composite's behavior. With the increased number of composites and the dependencies among them, it became necessary to manage all the metadata in an adequate way. This article will address the advantages of using the Oracle Metadata Services (MDS) repository as a central storage for the metadata. The MDS repository is a central part of the Oracle Fusion Middleware landscape, managing the metadata for several technologies, such as Oracle Application Development Framework (Oracle ADF), Oracle WebCenter, and the Oracle SOA Suite. This article is divided into three parts. The first part provides an overview of SCA and MDS. The second part describes some MDS tasks that help in the management of the SCA metadata files inside the repository. The third part shows how to develop SCA composites in combination with an MDS repository. Read the full article here. SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit  www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Technorati Tags: SCA Metadata. Metadata Services Repository,Nicolás Fonnegra Martinez,Markus Lohn,SOA Community,Oracle SOA,Oracle BPM,BPM,Community,OPN,Jürgen Kress

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• Points on lines where the two lines are the closest together

  - by James Bedford

  Hey guys, I'm trying to find the points on two lines where the two lines are the closest. I've implemented the following method (Points and Vectors are as you'd expect, and a Line consists of a Point on the line and a non-normalized direction Vector from that point): void CDClosestPointsOnTwoLines(Line line1, Line line2, Point* closestPoints) { closestPoints[0] = line1.pointOnLine; closestPoints[1] = line2.pointOnLine; Vector d1 = line1.direction; Vector d2 = line2.direction; float a = d1.dot(d1); float b = d1.dot(d2); float e = d2.dot(d2); float d = a*e - b*b; if (d != 0) // If the two lines are not parallel. { Vector r = Vector(line1.pointOnLine) - Vector(line2.pointOnLine); float c = d1.dot(r); float f = d2.dot(r); float s = (b*f - c*e) / d; float t = (a*f - b*c) / d; closestPoints[0] = line1.positionOnLine(s); closestPoints[1] = line2.positionOnLine(t); } else { printf("Lines were parallel.\n"); } } I'm using OpenGL to draw three lines that move around the world, the third of which should be the line that most closely connects the other two lines, the two end points of which are calculated using this function. The problem is that the first point of closestPoints after this function is called will lie on line1, but the second point won't lie on line2, let alone at the closest point on line2! I've checked over the function many times but I can't see where the mistake in my implementation is. I've checked my dot product function, scalar multiplication, subtraction, positionOnLine() etc. etc. So my assumption is that the problem is within this method implementation. If it helps to find the answer, this is function supposed to be an implementation of section 5.1.8 from 'Real-Time Collision Detection' by Christer Ericson. Many thanks for any help!

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• What are the best ways to cope with «one of those days»? [closed]

  - by Júlio Santos

  I work in a fast-paced startup and am absolutely in love with what I do. Still, I wake up to a bad mood as often as the next guy. I find that forcing myself to play out my day as usual doesn't help — in fact, it only makes it worse, possibly ruining my productivity for the rest of the week. There are several ways I can cope with this, for instance: dropping the current task for the day and getting that awesome but low-priority feature in place; doing some pending research for future development (i.e. digging up ruby gems); spending the day reading and educating myself; just taking the day off. The first three items are productive in themselves, and taking the day off recharges my coding mana for the rest of the week. Being a young developer, I'm pretty sure there's a multitude of alternatives that I haven't come across yet. How can programmers cope with off days? Edit: I am looking for answers related specifically to this profession. I therefore believe that coping with off days in our field is fundamentally different that doing so in other areas. Programmers (especially in a start-up) are a unique breed in this context in the sense that they tend to have a multitude of tasks at hand on any given moment, so they can easily switch between these without wreaking too much havoc. Programmers also tend to work based on clear, concise objectives — provided they are well managed either by themselves or a third party — and hence have a great deal of flexibility when it comes to managing their time. Finally, our line of work creates the opportunity — necessity, if you will — to fit a plethora of tasks not directly related to the current one, such as research and staying on top of new releases and software updates.

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• C#: Adding Functionality to 3rd Party Libraries With Extension Methods

  - by James Michael Hare

  Ever have one of those third party libraries that you love but it's missing that one feature or one piece of syntactical candy that would make it so much more useful?  This, I truly think, is one of the best uses of extension methods.  I began discussing extension methods in my last post (which you find here) where I expounded upon what I thought were some rules of thumb for using extension methods correctly.  As long as you keep in line with those (or similar) rules, they can often be useful for adding that little extra functionality or syntactical simplification for a library that you have little or no control over. Oh sure, you could take an open source project, download the source and add the methods you want, but then every time the library is updated you have to re-add your changes, which can be cumbersome and error prone.  And yes, you could possibly extend a class in a third party library and override features, but that's only if the class is not sealed, static, or constructed via factories. This is the perfect place to use an extension method!  And the best part is, you and your development team don't need to change anything!  Simply add the using for the namespace the extensions are in! So let's consider this example.  I love log4net!  Of all the logging libraries I've played with, it, to me, is one of the most flexible and configurable logging libraries and it performs great.  But this isn't about log4net, well, not directly.  So why would I want to add functionality?  Well, it's missing one thing I really want in the ILog interface: ability to specify logging level at runtime. For example, let's say I declare my ILog instance like so:     using log4net;     public class LoggingTest     {         private static readonly ILog _log = LogManager.GetLogger(typeof(LoggingTest));         ...     }     If you don't know log4net, the details aren't important, just to show that the field _log is the logger I have gotten from log4net. So now that I have that, I can log to it like so:     _log.Debug("This is the lowest level of logging and just for debugging output.");     _log.Info("This is an informational message.  Usual normal operation events.");     _log.Warn("This is a warning, something suspect but not necessarily wrong.");     _log.Error("This is an error, some sort of processing problem has happened.");     _log.Fatal("Fatals usually indicate the program is dying hideously."); And there's many flavors of each of these to log using string formatting, to log exceptions, etc.  But one thing there isn't: the ability to easily choose the logging level at runtime.  Notice, the logging levels above are chosen at compile time.  Of course, you could do some fun stuff with lambdas and wrap it, but that would obscure the simplicity of the interface.  And yes there is a Logger property you can dive down into where you can specify a Level, but the Level properties don't really match the ILog interface exactly and then you have to manually build a LogEvent and... well, it gets messy.  I want something simple and sexy so I can say:     _log.Log(someLevel, "This will be logged at whatever level I choose at runtime!");     Now, some purists out there might say you should always know what level you want to log at, and for the most part I agree with them.  For the most party the ILog interface satisfies 99% of my needs.  In fact, for most application logging yes you do always know the level you will be logging at, but when writing a utility class, you may not always know what level your user wants. I'll tell you, one of my favorite things is to write reusable components.  If I had my druthers I'd write framework libraries and shared components all day!  And being able to easily log at a runtime-chosen level is a big need for me.  After all, if I want my code to really be re-usable, I shouldn't force a user to deal with the logging level I choose. One of my favorite uses for this is in Interceptors -- I'll describe Interceptors in my next post and some of my favorites -- for now just know that an Interceptor wraps a class and allows you to add functionality to an existing method without changing it's signature.  At the risk of over-simplifying, it's a very generic implementation of the Decorator design pattern. So, say for example that you were writing an Interceptor that would time method calls and emit a log message if the method call execution time took beyond a certain threshold of time.  For instance, maybe if your database calls take more than 5,000 ms, you want to log a warning.  Or if a web method call takes over 1,000 ms, you want to log an informational message.  This would be an excellent use of logging at a generic level. So here was my personal wish-list of requirements for my task: Be able to determine if a runtime-specified logging level is enabled. Be able to log generically at a runtime-specified logging level. Have the same look-and-feel of the existing Debug, Info, Warn, Error, and Fatal calls.    Having the ability to also determine if logging for a level is on at runtime is also important so you don't spend time building a potentially expensive logging message if that level is off.  Consider an Interceptor that may log parameters on entrance to the method.  If you choose to log those parameter at DEBUG level and if DEBUG is not on, you don't want to spend the time serializing those parameters. Now, mine may not be the most elegant solution, but it performs really well since the enum I provide all uses contiguous values -- while it's never guaranteed, contiguous switch values usually get compiled into a jump table in IL which is VERY performant - O(1) - but even if it doesn't, it's still so fast you'd never need to worry about it. So first, I need a way to let users pass in logging levels.  Sure, log4net has a Level class, but it's a class with static members and plus it provides way too many options compared to ILog interface itself -- and wouldn't perform as well in my level-check -- so I define an enum like below.     namespace Shared.Logging.Extensions     {         // enum to specify available logging levels.         public enum LoggingLevel         {             Debug,             Informational,             Warning,             Error,             Fatal         }     } Now, once I have this, writing the extension methods I need is trivial.  Once again, I would typically /// comment fully, but I'm eliminating for blogging brevity:     namespace Shared.Logging.Extensions     {         // the extension methods to add functionality to the ILog interface         public static class LogExtensions         {             // Determines if logging is enabled at a given level.             public static bool IsLogEnabled(this ILog logger, LoggingLevel level)             {                 switch (level)                 {                     case LoggingLevel.Debug:                         return logger.IsDebugEnabled;                     case LoggingLevel.Informational:                         return logger.IsInfoEnabled;                     case LoggingLevel.Warning:                         return logger.IsWarnEnabled;                     case LoggingLevel.Error:                         return logger.IsErrorEnabled;                     case LoggingLevel.Fatal:                         return logger.IsFatalEnabled;                 }                                 return false;             }             // Logs a simple message - uses same signature except adds LoggingLevel             public static void Log(this ILog logger, LoggingLevel level, object message)             {                 switch (level)                 {                     case LoggingLevel.Debug:                         logger.Debug(message);                         break;                     case LoggingLevel.Informational:                         logger.Info(message);                         break;                     case LoggingLevel.Warning:                         logger.Warn(message);                         break;                     case LoggingLevel.Error:                         logger.Error(message);                         break;                     case LoggingLevel.Fatal:                         logger.Fatal(message);                         break;                 }             }             // Logs a message and exception to the log at specified level.             public static void Log(this ILog logger, LoggingLevel level, object message, Exception exception)             {                 switch (level)                 {                     case LoggingLevel.Debug:                         logger.Debug(message, exception);                         break;                     case LoggingLevel.Informational:                         logger.Info(message, exception);                         break;                     case LoggingLevel.Warning:                         logger.Warn(message, exception);                         break;                     case LoggingLevel.Error:                         logger.Error(message, exception);                         break;                     case LoggingLevel.Fatal:                         logger.Fatal(message, exception);                         break;                 }             }             // Logs a formatted message to the log at the specified level.              public static void LogFormat(this ILog logger, LoggingLevel level, string format,                                          params object[] args)             {                 switch (level)                 {                     case LoggingLevel.Debug:                         logger.DebugFormat(format, args);                         break;                     case LoggingLevel.Informational:                         logger.InfoFormat(format, args);                         break;                     case LoggingLevel.Warning:                         logger.WarnFormat(format, args);                         break;                     case LoggingLevel.Error:                         logger.ErrorFormat(format, args);                         break;                     case LoggingLevel.Fatal:                         logger.FatalFormat(format, args);                         break;                 }             }         }     } So there it is!  I didn't have to modify the log4net source code, so if a new version comes out, i can just add the new assembly with no changes.  I didn't have to subclass and worry about developers not calling my sub-class instead of the original.  I simply provide the extension methods and it's as if the long lost extension methods were always a part of the ILog interface! Consider a very contrived example using the original interface:     // using the original ILog interface     public class DatabaseUtility     {         private static readonly ILog _log = LogManager.Create(typeof(DatabaseUtility));                 // some theoretical method to time         IDataReader Execute(string statement)         {             var timer = new System.Diagnostics.Stopwatch();                         // do DB magic                                    // this is hard-coded to warn, if want to change at runtime tough luck!             if (timer.ElapsedMilliseconds > 5000 && _log.IsWarnEnabled)             {                 _log.WarnFormat("Statement {0} took too long to execute.", statement);             }             ...         }     }     Now consider this alternate call where the logging level could be perhaps a property of the class          // using the original ILog interface     public class DatabaseUtility     {         private static readonly ILog _log = LogManager.Create(typeof(DatabaseUtility));                 // allow logging level to be specified by user of class instead         public LoggingLevel ThresholdLogLevel { get; set; }                 // some theoretical method to time         IDataReader Execute(string statement)         {             var timer = new System.Diagnostics.Stopwatch();                         // do DB magic                                    // this is hard-coded to warn, if want to change at runtime tough luck!             if (timer.ElapsedMilliseconds > 5000 && _log.IsLogEnabled(ThresholdLogLevel))             {                 _log.LogFormat(ThresholdLogLevel, "Statement {0} took too long to execute.",                     statement);             }             ...         }     } Next time, I'll show one of my favorite uses for these extension methods in an Interceptor.

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• API Auth vs User Auth

  - by user1626384

  I have read many posts and articles on this topic but still cant connect the dots. I want to make a Rails app that is strictly a JSON API maybe using Sinatra or the rails-api gem. I also want to make both a web client app and an iPhone app which consumes the API. No plans on letting third party dev's use it. So I could create a separate username/password combination for both the web and mobile client and use HTTP Basic over SSL. Each app would have these values as configs in the source and use it to authenticate to the API so only these can make a call. Anyone else trying would get a 401 error returned. This would be considered handling the API authentication. The web and mobile client apps allow end users to sign up and read/write data to the API. When each user is created, I create and save a token in their profile. If a user successfully signs in, I send back the token. On each future read/write then also send along this token in the header. I get the token and lookup the user in the database and make the read/write. Does this sound like an appropriate way to handle it. For the web client, when I initially send back the token, where do I store it. In a cookie? Do I also drop a cookie to handle session state?

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• Time management and self improvement

  - by Filip

  Hi, I hope I can open a discussion on this topic as this is not a specific problem. It's a topic I hope to get some ideas on how people in similar situation as mine manage their time. OK, I'm a single developer on a software project for the last 6-8 months. The project I'm working on uses several technologies, mainly .net stuff: WPF, WF, NHibernate, WCF, MySql and other third party SDKs relevant for the project nature. My experience and knowledge vary, for example I have a lot of experience in WPF but much less in WCF. I work full time on the project and im curios on how other programmers which need to multi task in many areas manage their time. I'm a very applied type of person and prefer to code instead of doing research. I feel that doing research "might" slow down the progress of the project while I recognize that research and learning more in areas which I'm not so strong will ultimately make me more productive. How would you split up your daily time in productive coding time and time to and experiment, read blogs, go through tutorials etc. I would say that Im coding about 90%+ of my day and devoting some but very little time in research and acquiring new knowledge.

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• Calling Web Services in classic ASP

  - by cabhilash

    Last day my colleague asked me the provide her a solution to call the Web service from classic ASP. (Yes Classic ASP. still people are using this :D ) We can call web service SOAP toolkit also. But invoking the service using the XMLHTTP object was more easier & fast. To create the Service I used the normal Web Service in .Net 2.0 with [Webmethod] public class WebService1 : System.Web.Services.WebService { [WebMethod] public string HelloWorld(string name){return name + " Pay my dues :) "; // a reminder to pay my consultation fee :D} } In Web.config add the following entry in System.web<webServices><protocols><add name="HttpGet"/><add name="HttpPost"/></protocols></webServices> Alternatively, you can enable these protocols for all Web services on the computer by editing the <protocols> section in Machine.config. The following example enables HTTP GET, HTTP POST, and also SOAP and HTTP POST from localhost: <protocols> <add name="HttpSoap"/> <add name="HttpPost"/> <add name="HttpGet"/> <add name="HttpPostLocalhost"/> <!-- Documentation enables the documentation/test pages --> <add name="Documentation"/> </protocols> By adding these entries I am enabling the HTTPGET & HTTPPOST (After .Net 1.1 by default HTTPGET & HTTPPOST is disabled because of security concerns)The .NET Framework 1.1 defines a new protocol that is named HttpPostLocalhost. By default, this new protocol is enabled. This protocol permits invoking Web services that use HTTP POST requests from applications on the same computer. This is true provided the POST URL uses http://localhost, not http://hostname. This permits Web service developers to use the HTML-based test form to invoke the Web service from the same computer where the Web service resides. Classic ASP Code to call Web service <%Option Explicit Dim objRequest, objXMLDoc, objXmlNode Dim strRet, strError, strNome Dim strName strName= "deepa" Set objRequest = Server.createobject("MSXML2.XMLHTTP") With objRequest .open "GET", "http://localhost:3106/WebService1.asmx/HelloWorld?name=" & strName, False .setRequestHeader "Content-Type", "text/xml" .setRequestHeader "SOAPAction", "http://localhost:3106/WebService1.asmx/HelloWorld" .send End With Set objXMLDoc = Server.createobject("MSXML2.DOMDocument") objXmlDoc.async = false Response.ContentType = "text/xml" Response.Write(objRequest.ResponseText) %> In Line 6 I created an MSXML XMLHTTP object. Line 9 Using the HTTPGET protocol I am openinig connection to WebService Line 10:11 – setting the Header for the service In line 15, I am getting the output from the webservice in XML Doc format & reading the responseText(line 18). In line 9 if you observe I am passing the parameter strName to the Webservice You can pass multiple parameters to the Web service by just like any other QueryString Parameters. In similar fashion you can invoke the Web service using HTTPPost. Only you have to ensure that the form contains all th required parameters for webmethod.  Happy coding !!!!!!!

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• SQL SERVER – Question to You – When to use Function and When to use Stored Procedure

  - by pinaldave

  This week has been very interesting week. I have asked few questions to users and have received remarkable participation on the subject. Q1) SQL SERVER – Puzzle – SELECT * vs SELECT COUNT(*) Q2) SQL SERVER – Puzzle – Statistics are not Updated but are Created Once Keeping the same spirit up, I am asking the third question over here. Q3) When to use User Defined Function and when to use Stored Procedure in your development? Personally, I believe that they are both different things - they cannot be compared. I can say, it will be like comparing apples and oranges. Each has its own unique use. However, they can be used interchangeably at many times and in real life (i.e., production environment). I have personally seen both of these being used interchangeably many times. This is the precise reason for asking this question. When do you use Function and when do you use Stored Procedure? What are Pros and Cons of each of them when used instead of each other? If you are going to answer that ‘To avoid repeating code, you use Function’ - please think harder! Stored procedure can do the same. In SQL Server Denali, even the stored procedure can return the result just like Function in SELECT statement; so if you are going to answer with ‘Function can be used in SELECT, whereas Stored Procedure cannot be used’ - again think harder! (link). Now, what do you say? I will post the answers of all the three questions with due credit next week. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, Readers Question, SQL, SQL Authority, SQL Function, SQL Puzzle, SQL Query, SQL Server, SQL Stored Procedure, SQL Tips and Tricks, SQLServer, T SQL, Technology

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• Add game mechanics through equipment?

  - by Sidar

  In a game with different weapons and armor that actually affect more than just player stats, how would you achieve such effect? (These are just examples not concrete ideas ) For example we could have a handgun, uzi and then you have the graviton-gun. The first two would just shoot bullets, the third one does more than just shoot a simple projectile. It could allow the player to hold an enemy and drag it to use it as a meat shield. The player could also wear generic armor but at some point wears armor that can absorb projectiles. After absorbing enough projectiles you can shoot a giant blast. All these weapons/armor have different "behaviors" that either just raise stats or actually add new mechanics. In a simple case most guns would have similar properties and changing a few settings would create a new weapon (handgun shoots at an interval of x amount of seconds, lower this number and you have a machinegun). This obviously does not work if you intend to do more than just shoot projectiles. I'm pretty much stuck on writing the interface structure. While weapons and armor have different purposes they should both be able to process certain effects that change or add mechanics in the game world.

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• Clustering Basics and Challenges

  - by Karoly Vegh

  For upcoming posts it seemed to be a good idea to dedicate some time for cluster basic concepts and theory. This post misses a lot of details that would explode the articlesize, should you have questions, do not hesitate to ask them in the comments.  The goal here is to get some concepts straight. I can't promise to give you an overall complete definitions of cluster, cluster agent, quorum, voting, fencing, split brain condition, so the following is more of an explanation. Here we go. -------- Cluster, HA, failover, switchover, scalability -------- An attempted definition of a Cluster: A cluster is a set (2+) server nodes dedicated to keep application services alive, communicating through the cluster software/framework with eachother, test and probe health status of servernodes/services and with quorum based decisions and with switchover/failover techniques keep the application services running on them available. That is, should a node that runs a service unexpectedly lose functionality/connection, the other ones would take over the and run the services, so that availability is guaranteed. To provide availability while strictly sticking to a consistent clusterconfiguration is the main goal of a cluster.  At this point we have to add that this defines a HA-cluster, a High-Availability cluster, where the clusternodes are planned to run the services in an active-standby, or failover fashion. An example could be a single instance database. Some applications can be run in a distributed or scalable fashion. In the latter case instances of the application run actively on separate clusternodes serving servicerequests simultaneously. An example for this version could be a webserver that forwards connection requests to many backend servers in a round-robin way. Or a database running in active-active RAC setup.  -------- Cluster arhitecture, interconnect, topologies -------- Now, what is a cluster made of? Servers, right. These servers (the clusternodes) need to communicate. This of course happens over the network, usually over dedicated network interfaces interconnecting all the clusternodes. These connection are called interconnects.How many clusternodes are in a cluster? There are different cluster topologies. The most simple one is a clustered pair topology, involving only two clusternodes:  There are several more topologies, clicking the image above will take you to the relevant documentation. Also, to answer the question Solaris Cluster allows you to run up to 16 servers in a cluster. Where shall these clusternodes be placed? A very important question. The right answer is: It depends on what you plan to achieve with the cluster. Do you plan to avoid only a server outage? Then you can place them right next to eachother in the datacenter. Do you need to avoid DataCenter outage? In that case of course you should place them at least in different fire zones. Or in two geographically distant DataCenters to avoid disasters like floods, large-scale fires or power outages. We call this a stretched- or campus cluster, the clusternodes being several kilometers away from eachother. To cover really large distances, you probably need to move to a GeoCluster, which is a different kind of animal.  What is a geocluster? A Geographic Cluster in Solaris Cluster terms is actually a metacluster between two, separate (locally-HA) clusters.  -------- Cluster resource types, agents, resources, resource groups -------- So how does the cluster manage my applications? The cluster needs to start, stop and probe your applications. If you application runs, the cluster needs to check regularly if the application state is healthy, does it respond over the network, does it have all the processes running, etc. This is called probing. If the cluster deems the application is in a faulty state, then it can try to restart it locally or decide to switch (stop on node A, start on node B) the service. Starting, stopping and probing are the three actions that a cluster agent does. There are many different kinds of agents included in Solaris Cluster, but you can build your own too. Examples are an agent that manages (mounts, moves) ZFS filesystems, or the Oracle DB HA agent that cares about the database, or an agent that moves a floating IP address between nodes. There are lots of other agents included for Apache, Tomcat, MySQL, Oracle DB, Oracle Weblogic, Zones, LDoms, NFS, DNS, etc.We also need to clarify the difference between a cluster resource and the cluster resource group.A cluster resource is something that is managed by a cluster agent. Cluster resource types are included in Solaris cluster (see above, e.g. HAStoragePlus, HA-Oracle, LogicalHost). You can group cluster resources into cluster resourcegroups, and switch these groups together from one node to another. To stick to the example above, to move an Oracle DB service from one node to another, you have to switch the group between nodes, and the agents of the cluster resources in the group will do the following:  On node A Shut down the DB Unconfigure the LogicalHost IP the DB Listener listens on unmount the filesystem   Then, on node B: mount the FS configure the IP  startup the DB -------- Voting, Quorum, Split Brain Condition, Fencing, Amnesia -------- How do the clusternodes agree upon their action? How do they decide which node runs what services? Another important question. Running a cluster is a strictly democratic thing.Every node has votes, and you need the majority of votes to have the deciding power. Now, this is usually no problem, clusternodes think very much all alike. Still, every action needs to be governed upon in a productive system, and has to be agreed upon. Agreeing is easy as long as the clusternodes all behave and talk to eachother over the interconnect. But if the interconnect is gone/down, this all gets tricky and confusing. Clusternodes think like this: "My job is to run these services. The other node does not answer my interconnect communication, it must be down. I'd better take control and run the services!". The problem is, as I have already mentioned, clusternodes very much think alike. If the interconnect is gone, they all assume the other node is down, and they all want to mount the data backend, enable the IP and run the database. Double IPs, double mounts, double DB instances - now that is trouble. Also, in a 2-node cluster they both have only 50% of the votes, that is, they themselves alone are not allowed to run a cluster.  This is where you need a quorum device. According to Wikipedia, the "requirement for a quorum is protection against totally unrepresentative action in the name of the body by an unduly small number of persons.". They need additional votes to run the cluster. For this requirement a 2-node cluster needs a quorum device or a quorum server. If the interconnect is gone, (this is what we call a split brain condition) both nodes start to race and try to reserve the quorum device to themselves. They do this, because the quorum device bears an additional vote, that could ensure majority (50% +1). The one that manages to lock the quorum device (e.g. if it's an FC LUN, it SCSI reserves it) wins the right to build/run a cluster, the other one - realizing he was late - panics/reboots to ensure the cluster config stays consistent.  Losing the interconnect isn't only endangering the availability of services, but it also endangers the cluster configuration consistence. Just imagine node A being down and during that the cluster configuration changes. Now node B goes down, and node A comes up. It isn't uptodate about the cluster configuration's changes so it will refuse to start a cluster, since that would lead to cluster amnesia, that is the cluster had some changes, but now runs with an older cluster configuration repository state, that is it's like it forgot about the changes.  Also, to ensure application data consistence, the clusternode that wins the race makes sure that a server that isn't part of or can't currently join the cluster can access the devices. This procedure is called fencing. This usually happens to storage LUNs via SCSI reservation.  Now, another important question: Where do I place the quorum disk?  Imagine having two sites, two separate datacenters, one in the north of the city and the other one in the south part of it. You run a stretched cluster in the clustered pair topology. Where do you place the quorum disk/server? If you put it into the north DC, and that gets hit by a meteor, you lose one clusternode, which isn't a problem, but you also lose your quorum, and the south clusternode can't keep the cluster running lacking the votes. This problem can't be solved with two sites and a campus cluster. You will need a third site to either place the quorum server to, or a third clusternode. Otherwise, lacking majority, if you lose the site that had your quorum, you lose the cluster. Okay, we covered the very basics. We haven't talked about virtualization support, CCR, ClusterFilesystems, DID devices, affinities, storage-replication, management tools, upgrade procedures - should those be interesting for you, let me know in the comments, along with any other questions. Given enough demand I'd be glad to write a followup post too. Now I really want to move on to the second part in the series: ClusterInstallation.  Oh, as for additional source of information, I recommend the documentation: http://docs.oracle.com/cd/E23623_01/index.html, and the OTN Oracle Solaris Cluster site: http://www.oracle.com/technetwork/server-storage/solaris-cluster/index.html

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• Clarity Comics Comic Reader for Windows Phone 7

  Weve been really busy building all sorts custom Windows Phone 7 goodies lately.  One of the experiences weve been working on recently is a comic book reader  for WP7.  Here at Clarity we have particular individuals that are nuts about comics and codingso it was a no-brainer to knock this thing out.  Under the Covers There are a couple of components to this application that made it come together quickly.  First, as you know, WP7 runs Silverlight so we were able to leverage a bunch of silverlight assets we had hanging around from previous projects.  We were shocked to see the 80% code reuse claim was true!  Second, the application was built on the newly created Clarity Phone Framework (CP7).  This framework provides a platform that we can leverage to quickly wire up applications and get them out the door.  The framework includes gesture support, mapping controls, data visualization,  a special mvvm architecture for the phone, navigation animations, and a handful of other controls weve cooked up in our labslike voice recognition support.  (additional posts on the framework are coming soon) Third, the reading experience of the comic reader is driven by Deep Zoom.  We were pleasantly surprised to see that the windows phone 7 sdk worked nicely with Deep Zoom and the Deep Zoom composer.  We did have to add some hooks in there to get the gestures to work, but nothing too deep (no pun intended).  Unfortunately we cant release the code for this one just yet.  But rest-assured, there will be plenty more Windows Phone 7 and Silverlight goodies to come. Cheers!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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• Clarity Comics Comic Reader for Windows Phone 7

  Weve been really busy building all sorts custom Windows Phone 7 goodies lately.  One of the experiences weve been working on recently is a comic book reader  for WP7.  Here at Clarity we have particular individuals that are nuts about comics and codingso it was a no-brainer to knock this thing out.  Under the Covers There are a couple of components to this application that made it come together quickly.  First, as you know, WP7 runs Silverlight so we were able to leverage a bunch of silverlight assets we had hanging around from previous projects.  We were shocked to see the 80% code reuse claim was true!  Second, the application was built on the newly created Clarity Phone Framework (CP7).  This framework provides a platform that we can leverage to quickly wire up applications and get them out the door.  The framework includes gesture support, mapping controls, data visualization,  a special mvvm architecture for the phone, navigation animations, and a handful of other controls weve cooked up in our labslike voice recognition support.  (additional posts on the framework are coming soon) Third, the reading experience of the comic reader is driven by Deep Zoom.  We were pleasantly surprised to see that the windows phone 7 sdk worked nicely with Deep Zoom and the Deep Zoom composer.  We did have to add some hooks in there to get the gestures to work, but nothing too deep (no pun intended).  Unfortunately we cant release the code for this one just yet.  But rest-assured, there will be plenty more Windows Phone 7 and Silverlight goodies to come. Cheers!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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• Use a Free Tool to Edit, Delete, or Restore the Default Hosts File in Windows

  - by Lori Kaufman

  The hosts file in Windows contains mappings of IP addresses to host names, like an address book for your computer. Your PC uses IP addresses to find websites, so it needs to translate the host names into IP addresses to access websites. When you enter a host name in a browser to visit a website, that host name is looked up in DNS servers to find the IP address. If you enter IP addresses and host names for websites you visit often, these websites will load faster, because the hosts file is loaded into memory when Windows start and overrides DNS server queries, creating a shortcut to the sites. Because the hosts file is checked first, you can also use it to block websites from tracking your activities on the internet, as well as block ads, banners, third-party cookies, and other intrusive elements on webpages. Your computer has its own host address, known as its “localhost” address. The IP address for localhost is 127.0.0.1. To block sites and website elements, you can enter the host name for the unwanted site in the hosts file and associate it with the localhost address. Blocking ads and other undesirable webpage elements, can also speed up the loading of websites. You don’t have to wait for all those items to load. The default hosts file that comes with Windows does not contain any host name/IP address mappings. You can add mappings manually, such as the IP address 74.125.224.72 for www.google.com. As an example of blocking an ad server website, you can enter the following line in your hosts file to block doubleclick.net from serving you ads. How To Use USB Drives With the Nexus 7 and Other Android Devices Why Does 64-Bit Windows Need a Separate “Program Files (x86)” Folder? Why Your Android Phone Isn’t Getting Operating System Updates and What You Can Do About It

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• Part 2: Career development as a Software Developer without becoming a manager.

  - by albertpascual

  Seems like my previous post inspired by the work of Michael “Doc” Norton was a great success for the amount of emails I have received. Yet amazed how many people didn’t want to discuss their questions in the comments  sections. I would encourage people to be more public, still I would like to reply to all of you on this public media. I still welcome those emails. What I found out is that many people feels like me, they want to be developers and still be compensated for their experience without wanting to take a job as a manager. Their perfect day is a full day of coding and learning. Many believe their companies will never pay a manager’s salary to a developer no matter what. Most of you ask how to get the ball rolling. And is the later that I’m addressing here, the previous group, will never try. What companies understand developers value and where can I find them? This is a very difficult question to ask, I don’t have a list of those companies or departments, I have seen in my past signs in companies bending backwards to compensate, in more ways the monetary, a developer that is a good resource to them. Allowing the person to move out of the state and still let them work for the company from home is a sign that company goes by individual cases. Allowing them to go to conference that will not benefit the company is another big sign. Simple signs like flexible hours and letting some people work from home. To see those signs you need to be working in that company for awhile and look at the departments where the manager is taking care of their employees in individual cases. Look for the department where people get quiet extra perks, where some people in the department work from home or remotely. In my experience, but not always true, medium to big companies, are prompt to recognize good developers. Then again, some companies just don’t get it and is when you see many technical people managing developers. For all the people that email me stating that developers can also be very good managers, I do not disagree, I just think that a good developers loves writing code, when you remove that part the better salary isn’t enough to keep a developer happy. Burned out developers appreciate being promoted to managers. How do I know I work in a bad company? In my experience I have been a consultant and seen many companies, a few signs I have learned about companies that will not recognize good developers are: When the turn over is pretty high, when developers are moving out in a big rate, no rocket scientist needs to tap you in the shoulder. When the company is looking always to outsource their development resources. The product is not that interesting nor the company cares too much for their final result and support. Code sweat shops. You’ll know when you start working in one of those. Run for the hills! Where do I start? Disclaimer: I have only based this post on Michael “Doc” Norton, this is just my interpretation and ideas. First thing is to look at Michael “Doc” Norton presentation Take Control of Your Development Career http://docondev.blogspot.com/ That should be the first thing any developer should look and follow like it was a pattern. I would personally recommend to find some language or pattern you are interested with and learn it, learn something that will make you happy. Second, join a User Group and get involve in the community. There are hundreds of user groups, and I’m sure you’ll find one in your city or near you town. Code Camps are Developers Meet Ups are also good resources. Third, I would join a open source project you are interested or better yet, create a new open source project with the new technology that you have learn and get coding. Fourth, create a Twitter account and follow the people that talks about the technology you are interested on. If you follow this 4 steps above I think you’ll be on your way, after they are complete, when you release your Open Source project you can say that you accomplished the first steps. Now, do not expect anything to change in your career life, you are changing and should not expect anything in return, besides borrowing some time from sleeping and your family. Creating a good schedule may help you, I find wasted time in many places that I use. Flying for work is actually one of those that allows me to do my best work on a airplane, don’t need to borrow time from anywhere else. Making sure you always have a light, charged laptop is so important. Next steps following the Michael “Doc” Norton Pattern or my interpretation of. First, help run a user group or better yet, start a new user group. I’ll add, as well, go to one conference a year and free development events around your city; Code Camps, Geek Dinners, etc. There are many free events sponsored by different companies for developers to get to know their products, I highly recommend those as the way to get connected. Second, chose a mentor, this is a very hard thing to do I experienced, find an expert in the technology you are learning that has the time for you, it is difficult, I wish you best of luck. Third, learn another technology or pattern, open your horizons a little bit more. Why not, if you had fun previously, keep doing it. Fourth, get involved in forums to answer and ask questions, getting notice in public forums is rewarding for your ego after such a long journey. Final steps following the Michael “Doc” Norton Pattern Teach what you know, become humble on your knowledge, find as many opportunities to teach and to get involved with the community, bring all that to your day job. Mr. Norton talks about getting naked, expose yourself to others in your knowledge and what you do not know. You are never too important for small opportunities, yet don’t  be afraid to take anything big and learn from the experience. Anytime you have the opportunity to talk to somebody that has reach the point the community knows his or her name, means that you should learn from it. Take opportunities that won’t make you money, yet will make you happy. Sometimes you need to spend money and time. Register talks in Code Camps and Dev Meet Ups, those are free, also go to Conference, Development Summits and Geek Diners for example. One day, people will pay you to attend. When will all these pay off? I don’t know. I’m still in the path, there are a few things that during your journey you may get little acknowledgements that you are in the correct path. In my case I think those are the little signs that tells you about your journey. I got awarded the Microsoft Most Valuable Professional for ASP.NET in 2007, 2008, 2009 and 2010. I got selected to speak at the DevConnections in Las Vegas in 2010 and Orlando 2011. I do believe that I do have a long way to go, yet what I do makes me happy and I hope I can keep doing for years to come. Every year I can see an improvement on my code, and more frameworks and languages are under my belt, I learn to embrace them all as well as in my daily job, I have been able to work in a few projects beyond my department. I’m a learner and believer of the Michael “Doc” Norton pattern. Looking forward to learn more about it to be able to apply it better. In my short journey I now see my mistakes, I did a few things right, I have been listening the intelligent people and not being afraid to move along the technology changes. In my professional life, I have tried to avoid being placed in only one technology and product. I have always share my code and never confused anybody that wanted to take over any of my projects, I didn’t think anything I created as my own nor care too much when politics didn’t see my vision. I stayed flexible, ready and visible, yet humble. I keep my head just below the clouds, and avoided managers meetings. I credit my manager for my success, and I faulted publicly only myself for the failures. Hope this helps. Cheers, Al Follow me in Twitter  Read my previous post tweetmeme_url = 'http://weblogs.asp.net/albertpascual/archive/2010/12/09/part-2-career-development-as-a-software-developer-without-becoming-a-manager.aspx'; tweetmeme_source = 'alpascual';

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• NASA’s can alert you when Space Station is visible from your backyard

  - by Gopinath

  NASA’s International Space Station(ISS) is the third most brightest object visible in the sky after Sun and Moon. If we know exactly when to look up, we will be able to spot Space Station with naked eye and it looks like bright star moving.  On the occasion of 12th anniversary of astronauts living in space station, NASA started a free services dubbed as Spot The Station, that alerts you when Space Station is visible from your backyard. Those who sign up with the free service by providing location details will get an email & text alerts couple of hours in advance so that they can have a glimpse of space station. Here is a sample alert sent to registered users SpotTheStation! Time: Wed Apr 25 7:45 PM, Visible: 4 min, Max Height: 66 degrees, Appears: WSW, Disappears NE. The space station is typically visible right at early morning or evenings when moon is the only one brightest star visible in the sky. The service is available world wide and almost 90 percent of the population on earth would be able to see clearly without using any fancy equipment. Follow the link spotthestation.nasa.gov to register for alerts. Flickr cc image: slideshow bob

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• How to Change Ubuntu’s Window Borders with Emerald

  - by The Geek

  The look of your operating system is all about the panels and the window borders, so now that we’ve shown you how to customize your panels, it’s time to customize the window borders to make Ubuntu look the way you want it to. For the purposes of this article, we’re going to assume that you’ve got the Compiz compositing window manager running—which is what provides the custom window effects found in Ubuntu. This means the technique probably won’t work in a virtual machine, or a really old PC. This is the third installment of our series on customizing Ubuntu by geeky reader Omar Hafiz—be sure and check out the first article, where he explained how to make your panels transparent, and the second article, where he explained how to customize the fonts and colors of those panels Latest Features How-To Geek ETC How To Make Hundreds of Complex Photo Edits in Seconds With Photoshop Actions How to Enable User-Specific Wireless Networks in Windows 7 How to Use Google Chrome as Your Default PDF Reader (the Easy Way) How To Remove People and Objects From Photographs In Photoshop Ask How-To Geek: How Can I Monitor My Bandwidth Usage? Internet Explorer 9 RC Now Available: Here’s the Most Interesting New Stuff Never Call Me at Work [Humorous Star Wars Video] Add an Image Properties Listing to the Context Menu in Chrome and Iron Add an Easy to View Notification Badge to Tabs in Firefox SpellBook Parks Bookmarklets in Chrome’s Context Menu Drag2Up Brings Multi-Source Drag and Drop Uploading to Firefox Enchanted Swing in the Forest Wallpaper

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• Idea for a physics–computer science joint curriculum and textbook

  - by Ami

  (I apologize in advance if this question is off topic or too vague) I want to write (and have starting outlining) a physics textbook which assumes its reader is a competent computer programmer. Normal physics textbooks teach physical formulas and give problems that are solved with pen, paper and calculator. I want to provide a book that emphasizes computational physics, how computers can model physical systems and gives problems of the kind: write a program that can solve a set of physics problems based on user input. Third party open source libraries would be used to handle most of the computation and I want to use a high-level language like Java or C#. Besides the fact I'd enjoy working on this, I think a physics-computer science joint curriculum should be offered in schools and this is part of a large agenda to make this happen. I think physics students (like myself) should be learning how to use and leverage computers to solve abstract problems and sets of problems. I think programming languages should be thought of as a useful medium for engaging in many areas of inquiry. Is this an idea worth pursuing? Is the merger of these two subjects in the form of an undergraduate college curriculum feasible? Are there any specific tools I should be leveraging or pitfalls I should be aware of? Has anyone heard of college courses or otherwise that assume this methodology? Are there any books/textbooks out there like the one I'm describing (for physics or any other subject)?

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• SQL SERVER – Understanding XML – Contest Win Joes 2 Pros Combo (USD 198) – Day 5 of 5

  - by pinaldave

  August 2011 we ran a contest where every day we give away one book for an entire month. The contest had extreme success. Lots of people participated and lots of give away. I have received lots of questions if we are doing something similar this month. Absolutely, instead of running a contest a month long we are doing something more interesting. We are giving away USD 198 worth gift every day for this week. We are giving away Joes 2 Pros 5 Volumes (BOOK) SQL 2008 Development Certification Training Kit every day. One copy in India and One in USA. Total 2 of the giveaway (worth USD 198). All the gifts are sponsored from the Koenig Training Solution and Joes 2 Pros. The books are available here Amazon | Flipkart | Indiaplaza How to Win: Read the Question Read the Hints Answer the Quiz in Contact Form in following format Question Answer Name of the country (The contest is open for USA and India residents only) 2 Winners will be randomly selected announced on August 20th. Question of the Day: Is following XML a well formed XML Document? <?xml version=”1.0″?> <address> <firstname>Pinal</firstname> <lastname>Dave</lastname> <title>Founder</title> <company>SQLAuthority.com</company> </address> a) Yes b) No c) I do not know Query Hints: BIG HINT POST A common observation by people seeing an XML file for the first time is that it looks like just a bunch of data inside a text file. XML files are text-based documents, which makes them easy to read.  All of the data is literally spelled out in the document and relies on a just a few characters (<, >, =) to convey relationships and structure of the data.  XML files can be used by any commonly available text editor, like Notepad. Much like a book’s Table of Contents, your first glance at well-formed XML will tell you the subject matter of the data and its general structure. Hints appearing within the data help you to quickly identify the main theme (similar to book’s subject), its headers (similar to chapter titles or sections of a book), data elements (similar to a book’s characters or chief topics), and so forth. We’ll learn to recognize and use the structural “hints,” which are XML’s markup components (e.g., XML tags, root elements). The XML Raw and Auto modes are great for displaying data as all attributes or all elements – but not both at once. If you want your XML stream to have some of its data shown in attributes and some shown as elements, then you can use the XML Path mode. If you are using an XML Path stream, then by default all values will be shown as elements. However, it is possible to pick one or more elements to be shown with an attribute(s) as well. Additional Hints: I have previously discussed various concepts from SQL Server Joes 2 Pros Volume 5. SQL Joes 2 Pros Development Series – OpenXML Options SQL Joes 2 Pros Development Series – Preparing XML in Memory SQL Joes 2 Pros Development Series – Shredding XML SQL Joes 2 Pros Development Series – Using Root With Auto XML Mode SQL Joes 2 Pros Development Series – Using Root With Auto XML Mode SQL Joes 2 Pros Development Series – What is XML? SQL Joes 2 Pros Development Series – What is XML? – 2 Next Step: Answer the Quiz in Contact Form in following format Question - Answer Name of the country (The contest is open for USA and India) Bonus Winner Leave a comment with your favorite article from the “additional hints” section and you may be eligible for surprise gift. There is no country restriction for this Bonus Contest. Do mention why you liked it any particular blog post and I will announce the winner of the same along with the main contest. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• .NET Reflector & .NET Reflector Pro 6.1 have been released

  - by Bart Read

  .NET Reflector 6.1 and .NET Reflector Pro 6.1 have been released. You can download them from: http://www.red-gate.com/products/reflector/index.htm .NET Reflector is a class browser and disassembler for .NET assemblies. .NET Reflector Pro is a Visual Studio debugging extension that allows you to step through third party and framework assemblies, as if they were built from your own source code. This release fixes several problems that were present in the 6.0 release: Support for using a copy of Reflector.cfg stored alongside Reflector.exe has been re-enabled so users upgrading from 5.x releases will not lose their settings. Fixed unhandled exception on exit of Visual Studio when .NET Reflector add-in used in conjunction with TestDriven.NET add-in. Added better support for dealing with framework assemblies, which only contain meta-data, in the "Referenced Assemblies" folder. Fixed problem where attempted decompilation with CppCliLanguage add-in would lead to display of a page on the Red Gate website. Added option to activate .NET Reflector Pro to .NET Reflector menu in Visual Studio after receiving feedback from a number of users that it was hard to figure out how to activate the product. For more details about the products please visit: http://www.red-gate.com/products/reflector/index.htm

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• Java Spotlight Episode 86: Tony Printezis on Garbage Collection First

  - by Roger Brinkley

  Interview with Tony Printezis on Garbage Collection First (GC1). Joining us this week on the Java All Star Developer Panel is Arun Gupta, Java EE Guy. Right-click or Control-click to download this MP3 file. You can also subscribe to the Java Spotlight Podcast Feed to get the latest podcast automatically. If you use iTunes you can open iTunes and subscribe with this link:  Java Spotlight Podcast in iTunes. Show Notes News JSR 358: A major revison of the Java Community Process - JCP 3.Next JAX-RS 2.0 Early Draft- Third Edition Events June 11-14, Cloud Computing Expo, New York City June 12, Boulder JUG June 13, Denver JUG June 13, Eclipse Juno DemoCamp, Redwoood Shore June 13, JUG Münster June 14, Java Klassentreffen, Vienna, Austria June 18-20, QCon, New York City June 19, CJUG, Chicago June 20, 1871, Chicago June 26-28, Jazoon, Zurich, Switzerland Jun 27, Houston JUG ?? July 5, Java Forum, Stuttgart, Germany Jul 13-14, IndicThreads, Delhi July 30-August 1, JVM Language Summit, Santa Clara Feature InterviewTony Printezis is a Principal Member of Technical Staff at Oracle, based in Burlington, MA. He has been contributing to the Java HotSpot Virtual Machine since 2006. He spends most of his time working on dynamic memory management for the Java platform, concentrating on performance, scalability, responsiveness, parallelism, and visualization of garbage collectors. He obtained a Ph.D. in 2000 and a BSc (Hons) in 1995, both from the University of Glasgow in Scotland. In addition, he is a JavaOne Rock Star, a title awarded for his highly rated JavaOne session on GC. Mail Bag What’s Cool JavaOne content selection is complete. Notifications done.

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• OSI Model

  - by kaleidoscope

  The Open System Interconnection Reference Model (OSI Reference Model or OSI Model) is an abstract description for layered communications and computer network protocol design. In its most basic form, it divides network architecture into seven layers which, from top to bottom, are the Application, Presentation, Session, Transport, Network, Data Link, and Physical Layers. It is therefore often referred to as the OSI Seven Layer Model. A layer is a collection of conceptually similar functions that provide services to the layer above it and receives service from the layer below it. Description of OSI layers: Layer 1: Physical Layer ·         Defines the electrical and physical specifications for devices. In particular, it defines the relationship between a device and a physical medium. ·         Establishment and termination of a connection to a communications medium. ·         Participation in the process whereby the communication resources are effectively shared among multiple users. ·         Modulation or conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications channel. Layer 2: Data Link Layer ·         Provides the functional and procedural means to transfer data between network entities. ·         Detect and possibly correct errors that may occur in the Physical Layer. The error check is performed using Frame Check Sequence (FCS). ·         Addresses is then sought to see if it needs to process the rest of the frame itself or whether to pass it on to another host. ·         The Layer is divided into two sub layers: The Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. ·         MAC sub layer controls how a computer on the network gains access to the data and permission to transmit it. ·         LLC layer controls frame synchronization, flow control and error checking.   Layer 3: Network Layer ·         Provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks. ·         Performs network routing functions, and might also perform fragmentation and reassembly, and report delivery errors. ·         Network Layer Routers operate at this layer—sending data throughout the extended network and making the Internet possible.   Layer 4: Transport Layer ·         Provides transparent transfer of data between end users, providing reliable data transfer services to the upper layers. ·         Controls the reliability of a given link through flow control, segmentation/de-segmentation, and error control. ·         Transport Layer can keep track of the segments and retransmit those that fail. Layer 5: Session Layer ·         Controls the dialogues (connections) between computers. ·         Establishes, manages and terminates the connections between the local and remote application. ·         Provides for full-duplex, half-duplex, or simplex operation, and establishes checkpointing, adjournment, termination, and restart procedures. ·         Implemented explicitly in application environments that use remote procedure calls. Layer 6: Presentation Layer ·         Establishes a context between Application Layer entities, in which the higher-layer entities can use different syntax and semantics, as long as the presentation service understands both and the mapping between them. The presentation service data units are then encapsulated into Session Protocol data units, and moved down the stack. ·         Provides independence from differences in data representation (e.g., encryption) by translating from application to network format, and vice versa. The presentation layer works to transform data into the form that the application layer can accept. This layer formats and encrypts data to be sent across a network, providing freedom from compatibility problems. It is sometimes called the syntax layer. Layer 7: Application Layer ·         This layer interacts with software applications that implement a communicating component. ·         Identifies communication partners, determines resource availability, and synchronizes communication. o       When identifying communication partners, the application layer determines the identity and availability of communication partners for an application with data to transmit. o       When determining resource availability, the application layer must decide whether sufficient network or the requested communication exists. o       In synchronizing communication, all communication between applications requires cooperation that is managed by the application layer. Technorati Tags: Kunal,OSI,Networking

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• NuGet, ASP.Net MVC and WebMatrix - DB Coders Cafe - March 1st, 2011 With Sam Abraham

  - by Sam Abraham

  I am scheduled to share on NuGet (http://nuget.codeplex.com/) at the Deerfield Beach Coder’s Café on March 1st, 2011. My goal for this talk is to present demos and content covering how to leverage this new neat utility to easily “package” .Net-based binaries or tools and share them with others, who in-turn, can just as easy reference and readily use that same package in their Visual Studio 2010 .Net projects. Scott Hanselman has recently blogged in great detail on creating NuGet packages. For hosting a local NuGet package repository, Jon Galloway has a nice article update with a complete PowerShell script to simplify downloading the default feed packages which can be accessed here. Information on my upcoming talk can be found at: http://www.fladotnet.com/Reg.aspx?EventID=514 The following is a brief abstract of the talk: NuGet (formerly known as NuPack) is a free, open source developer focused package management system for the .NET platform intent on simplifying the process of incorporating third party libraries into a .NET application during development. NuGet is a member of the ASP.NET Gallery in the Outercurve Foundation. In this session we will: Discuss the concept, vision and goal behind NuGet See NuGet in action within an ASP.Net MVC project Look at the NuGet integration in Microsoft WebMatrix Create a NuGet package for our demo library Explore the NuGet Project site Configure a NuGet package feed for a local network Solicit attendees input and feedback on the tool  Look forward to meeting you all there. --Sam

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• SQL SERVER – Where Can YOU Get My Books – SQL Server Interview Question and Answers

  - by pinaldave

  Earlier month I released by third book SQL Server Interview Question and Answers. The focus of this book is ‘master the basics’. If you rate yourself 10 out of 10 in SQL Server – this book is not for you but if you want to learn fundamentals or want to refresh your fundamentals this book is for YOU. Earlier I was overwhelmed by love you all have shown to this book on release date leading our three digit inventory to run out of stock. Read detail blog post about the subject over here A Real Story of Book Getting ‘Out of Stock’ to A 25% Discount Story Available. Well, we learn the lesson from the experience and have made sure that the inventory does not run out any more. Since then we are now available on multiple outlets. Pretty much anywhere in USA and India the book is available. Additionally, where ever Amazon ships internationally. I have created dedicated page where I have listed where one can avail this book from Details of SQL Server Interview Question and Answers. Even though I keep on getting common question like – where one can get this book. You can get this book from: USA: Amazon India: Flipkart | IndiaPlaza | Crossword In India now you can walk into any crossword store and ask this book, if they do not have it, you can ask them get one for you. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Pinal Dave, PostADay, SQL, SQL Authority, SQL Documentation, SQL Download, SQL Interview Questions and Answers, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, SQLAuthority Book Review, SQLAuthority News, T SQL, Technology

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• Time management and self improvement

  - by Filip

  I hope I can open a discussion on this topic as this is not a specific problem. It's a topic I hope to get some ideas on how people in similar situation as mine manage their time. OK, I'm a single developer on a software project for the last 6-8 months. The project I'm working on uses several technologies, mainly .net stuff: WPF, WF, NHibernate, WCF, MySql and other third party SDKs relevant for the project nature. My experience and knowledge vary, for example I have a lot of experience in WPF but much less in WCF. I work full time on the project and im curios on how other programmers which need to multi task in many areas manage their time. I'm a very applied type of person and prefer to code instead of doing research. I feel that doing research "might" slow down the progress of the project while I recognize that research and learning more in areas which I'm not so strong will ultimately make me more productive. How would you split up your daily time in productive coding time and time to and experiment, read blogs, go through tutorials etc. I would say that Im coding about 90%+ of my day and devoting some but very little time in research and acquiring new knowledge. Thanks for your replies. I think I will adopt a gradual transition to Dominics block parts. I kinda knew that coding was taking up way to much of my time but it feels good having a first version of the project completed and ready. With a few months of focused hard work behind me I hope to get more time to experiment and expand my knowlegde. Now I only hope my boss will cut me some slack and stop pressuring me for features...

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