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• Oracle Exalogic Customer Momentum @ OOW'12

  - by Sanjeev Sharma

  [Adapted from here]  At Oracle Open World 2012, i sat down with some of the Oracle Exalogic early adopters  to discuss the business benefits these businesses were realizing by embracing the engineered systems approach to data-center modernization and application consolidation. Below is an overview of the 4 businesses that won the Oracle Fusion Middleware Innovation Award for Oracle Exalogic this year. Company: Netshoes About: Leading online retailer of sporting goods in Latin America.Challenges: Rapid business growth resulted in frequent outages and poor response-time of online store-front Conventional ad-hoc approach to horizontal scaling resulted in high CAPEX and OPEX Poor performance and unavailability of online store-front resulted in revenue loss from purchase abandonment Solution: Consolidated ATG Commerce and Oracle WebLogic running on Oracle Exalogic.Business Impact:Reduced abandonment rates resulting in a two-digit increase in online conversion rates translating directly into revenue up-liftCompany: ClaroAbout: Leading communications services provider in Latin America.Challenges: Support business growth over the next 3  - 5 years while maximizing re-use of existing middleware and application investments with minimal effort and risk Solution: Consolidated Oracle Fusion Middleware components (Oracle WebLogic, Oracle SOA Suite, Oracle Tuxedo) and JAVA applications onto Oracle Exalogic and Oracle Exadata. Business Impact:Improved partner SLA’s 7x while improving throughput 5X and response-time 35x for  JAVA applicationsCompany: ULAbout: Leading safety testing and certification organization in the world.Challenges: Transition from being a non-profit to a profit oriented enterprise and grow from a $1B to $5B in annual revenues in the next 5 years Undertake a massive business transformation by aligning change strategy with execution Solution: Consolidated Oracle Applications (E-Business Suite, Siebel, BI, Hyperion) and Oracle Fusion Middleware (AIA, SOA Suite) on Oracle Exalogic and Oracle ExadataBusiness Impact:Reduced financial and operating risk in re-architecting IT services to support new business capabilities supporting 87,000 manufacturersCompany: Ingersoll RandAbout: Leading manufacturer of industrial, climate, residential and security solutions.Challenges: Business continuity risks due to complexity in enforcing consistent operational and financial controls; Re-active business decisions reduced ability to offer differentiation and compete Solution: Consolidated Oracle E-business Suite on Oracle Exalogic and Oracle ExadataBusiness Impact:Service differentiation with faster order provisioning and a shorter lead-to-cash cycle translating into higher customer satisfaction and quicker cash-conversionCheck out the winners of the Oracle Fusion Middleware Innovation awards in other categories here.

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• Do programmers need a union? [closed]

  - by James A. Rosen

  In light of the acrid responses to the intellectual property clause discussed in my previous question, I have to ask: why don't we have a programmers' union? There are many issues we face as employees, and we have very little ability to organize and negotiate. Could we band together with the writers', directors', or musicians' guilds, or are our needs unique? Has anyone ever tried to start one? If so, why did it fail? (Or, alternatively, why have I never heard of it, despite its success?) later: Keith has my idea basically right. I would also imagine the union being involved in many other topics, including: legal liability for others' use/misuse of our work, especially unintended uses evaluating the quality of computer science and software engineering higher education programs -- unlike many other engineering disciplines, we are not required to be certified on receiving our Bachelor's degrees evangelism and outreach -- especially to elementary school students certification -- not doing it, but working with the companies like ISC(2) and others to make certifications meaningful and useful continuing education -- similar to previous conferences -- maintain a go-to list of organizers and other resources our members can use I would see it less so as a traditional trade union, with little emphasis on: pay -- we tend to command fairly good salaries outsourcing and free trade -- most of use tend to be pretty free-market oriented working conditions -- we're the only industry with Aeron chairs being considered anything like "standard"

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• SpringMvc java.lang.NullPointerException When Posting Form To Server [closed]

  - by dev_darin

  I have a form with a user name field on it when i tab out of the field i use a RESTFUL Web Service that makes a call to a handler method in the controller. The method makes a call to a DAO class that checks the database if the user name exists. This works fine, however when the form is posted to the server i call the same exact function i would call in the handler method however i get a java.lang.NullPointerException when it accesses the class that makes a call to the DAO object. So it does not even access the DAO object the second time. I have exception handlers around the calls in all my classes that makes calls. Any ideas as to whats happening here why i would get the java.lang.NullPointerException the second time the function is called.Does this have anything to do with Spring instantiating DAO classes using a Singleton method or something to that effect? What can be done to resolve this? This is what happens the First Time The Method is called using the Web Service(this is suppose to happen): 13011 [http-8084-2] INFO com.crimetrack.jdbc.JdbcOfficersDAO - Inside jdbcOfficersDAO 13031 [http-8084-2] DEBUG org.springframework.jdbc.core.JdbcTemplate - Executing prepared SQL query 13034 [http-8084-2] DEBUG org.springframework.jdbc.core.JdbcTemplate - Executing prepared SQL statement [SELECT userName FROM crimetrack.tblofficers WHERE userName = ?] 13071 [http-8084-2] DEBUG org.springframework.jdbc.datasource.DataSourceUtils - Fetching JDBC Connection from DataSource 13496 [http-8084-2] DEBUG org.springframework.jdbc.core.StatementCreatorUtils - Setting SQL statement parameter value: column index 1, parameter value [adminz], value class [java.lang.String], SQL type unknown 13534 [http-8084-2] DEBUG org.springframework.jdbc.datasource.DataSourceUtils - Returning JDBC Connection to DataSource 13537 [http-8084-2] INFO com.crimetrack.jdbc.JdbcOfficersDAO - No username was found in exception 13537 [http-8084-2] INFO com.crimetrack.service.ValidateUserNameManager - UserName :adminz does NOT exist The Second time When The Form Is 'Post' and a validation method handles the form and calls the same method the web service would call: 17199 [http-8084-2] INFO com.crimetrack.service.OfficerRegistrationValidation - UserName is not null so going to check if its valid for :adminz 17199 [http-8084-2] INFO com.crimetrack.service.OfficerRegistrationValidation - User Name in try.....catch block is adminz 17199 [http-8084-2] INFO com.crimetrack.service.ValidateUserNameManager - Inside Do UserNameExist about to validate with username : adminz 17199 [http-8084-2] INFO com.crimetrack.service.ValidateUserNameManager - UserName :adminz EXCEPTION OCCURED java.lang.NullPointerException ValidateUserNameManager.java public class ValidateUserNameManager implements ValidateUserNameIFace { private OfficersDAO officerDao; private final Logger logger = Logger.getLogger(getClass()); public boolean DoesUserNameExist(String userName) throws Exception { logger.info("Inside Do UserNameExist about to validate with username : " + userName); try{ if(officerDao.OfficerExist(userName) == true){ logger.info("UserName :" + userName + " does exist"); return true; }else{ logger.info("UserName :" + userName + " does NOT exist"); return false; } }catch(Exception e){ logger.info("UserName :" + userName + " EXCEPTION OCCURED " + e.toString()); return false; } } /** * @return the officerDao */ public OfficersDAO getOfficerDao() { return officerDao; } /** * @param officerdao the officerDao to set */ public void setOfficerDao(OfficersDAO officerDao) { this.officerDao = officerDao; } } JdbcOfficersDAO.java public boolean OfficerExist(String userName){ String dbUserName; try{ logger.info("Inside jdbcOfficersDAO"); String sql = "SELECT userName FROM crimetrack.tblofficers WHERE userName = ?"; try{ dbUserName = (String)getJdbcTemplate().queryForObject(sql, new Object[]{userName},String.class); logger.info("Just Returned from database"); }catch(Exception e){ logger.info("No username was found in exception"); return false; } if(dbUserName == null){ logger.info("Database did not find any matching records"); } logger.info("after JdbcTemplate"); if (dbUserName.equals(userName)) { logger.info("User Name Exists"); return true; }else{ logger.info("User Name Does NOT Exists"); return false; } }catch(Exception e){ logger.info("Exception Message in JdbcOfficersDAO is "+e.getMessage()); return false; } } OfficerRegistrationValidation.java public class OfficerRegistrationValidation implements Validator{ private final Logger logger = Logger.getLogger(getClass()); private ValidateUserNameManager validateUserNameManager; public boolean supports(Class<?> clazz) { return Officers.class.equals(clazz); } public void validate(Object target, Errors errors) { Officers officer = (Officers) target; if (officer.getUserName() == null){ errors.rejectValue("userName", "userName.required"); }else{ String userName = officer.getUserName(); logger.info("UserName is not null so going to check if its valid for :" + userName); try { logger.info("User Name in try.....catch block is " + userName); if (validateUserNameManager.DoesUserNameExist(userName)== true){ errors.rejectValue("userName", "userName.exist"); } } catch (Exception e) { logger.info("Error Occured When validating UserName"); errors.rejectValue("userName", "userName.error"); } } if(officer.getPassword()== null){ errors.rejectValue("password", "password.required"); } if(officer.getPassword2()== null){ errors.rejectValue("password2", "password2.required"); } if(officer.getfName() == null){ errors.rejectValue("fName","fName.required"); } if(officer.getlName() == null){ errors.rejectValue("lName", "lName.required"); } if (officer.getoName() == null){ errors.rejectValue("oName", "oName.required"); } if (officer.getEmailAdd() == null){ errors.rejectValue("emailAdd", "emailAdd.required"); } if (officer.getDob() == null){ errors.rejectValue("dob", "dob.required"); } if (officer.getGenderId().equals("A")){ errors.rejectValue("genderId","genderId.required"); } if(officer.getDivisionNo() == 1){ errors.rejectValue("divisionNo", "divisionNo.required"); } if(officer.getPositionId() == 1){ errors.rejectValue("positionId", "positionId.required"); } if (officer.getStartDate() == null){ errors.rejectValue("startDate","startDate.required"); } if(officer.getEndDate() == null){ errors.rejectValue("endDate","endDate.required"); } logger.info("The Gender ID is " + officer.getGenderId().toString()); if(officer.getPhoneNo() == null){ errors.rejectValue("phoneNo", "phoneNo.required"); } } /** * @return the validateUserNameManager */ public ValidateUserNameManager getValidateUserNameManager() { return validateUserNameManager; } /** * @param validateUserNameManager the validateUserNameManager to set */ public void setValidateUserNameManager( ValidateUserNameManager validateUserNameManager) { this.validateUserNameManager = validateUserNameManager; } } Update Error Log using Logger.Error("Message", e): 39024 [http-8084-2] INFO com.crimetrack.service.OfficerRegistrationValidation - UserName is not null so going to check if its valid for :adminz 39025 [http-8084-2] INFO com.crimetrack.service.OfficerRegistrationValidation - User Name in try.....catch block is adminz 39025 [http-8084-2] ERROR com.crimetrack.service.OfficerRegistrationValidation - Message java.lang.NullPointerException at com.crimetrack.service.OfficerRegistrationValidation.validate(OfficerRegistrationValidation.java:47) at org.springframework.validation.DataBinder.validate(DataBinder.java:725) at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.doBind(HandlerMethodInvoker.java:815) at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveHandlerArguments(HandlerMethodInvoker.java:367) at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:171) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:436) at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:424) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882) at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789) at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) at java.lang.Thread.run(Unknown Source) 39025 [http-8084-2] INFO com.crimetrack.service.OfficerRegistrationValidation - Error Occured When validating UserName

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• TellagoStudio's presenting SOA Governance on the Microsoft platform using SO-Aware at Microsoft TechReady.

  - by Vishal

  Hi there, Microsoft is hosting the first edition of their annual TechReddy conference. TechReady is an internal Microsoft conference but Microsoft invited Tellago Studios to present a session about how to enable Agile SOA Governance on the Microsoft platform using our recently release product: SO-Aware. As part of our session, we will take a look at the current challenges that organizations face when enabling SOA governance capabilities on the Microsoft platform and how organizations can benefit from  more agile, lightweight and modern SOA governance models. The session will provide a practical view to the role of Tellago Studios' SO-Aware as an essential technology to enable native SOA governance on the Microsoft platform. We will explore in detail important capabilities of SO-Aware such as Centralized service repository Centralized configuration management Service testing Monitoring Transparent integration with technologies such as Visual Studio, BizTalk Server, Windows Server & Azure AppFabric among many others But the fun doesn't stop there..... As part of this session, we will showcase for the first time our upcoming SO-Aware Test Workbench product which enables load and functional web service testing capabilities on the Microsoft technology stack. SO-Aware Test Workbench provides developers with a visually rich environment to model and control the execution of load and functional tests in a SOA infrastructure. This tool includes the first native WCF load testing engine allowing developers to transparently load test applications built on Microsoft's service oriented technologies such as WCF, BizTalk Server or the Windows Server or Azure AppFabric.

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• Turn-based Client-Server Card Game - Unicast (TCP) or Multicast (UDP)

  - by LDM91

  I am currently planning to make a card game project where the clients will communicate with the server in a turn-based and synchronous manner using messages sent over sockets. The problem I have is how to handle the following scenario: (Client takes it turn and sends its action to server) Client sends a message telling the server its move for the turn (e.g. plays the card 5 from its hand which needs to placed onto the table) Server receives messages and updates game state (server will hold all game state). Server iterates through a list of connected clients and sends a message to tell of them change in state Clients all refresh to display the state This is all based on using TCP, and looking at it now it seems a bit like the Observer pattern. The reason this seems to be an issue to me is this message doesn't seem to be point-to-point like the others as I want to send it to all the clients, and doesn't seem very efficient sending the same message in that way. I was thinking about using multicasting with UDP as then I could send the message to all the clients, however wouldn't this mean that the clients would in theory be able to message each other? There is of course the synchronous aspect as well, though this could be put on top of the UDP I guess. Basically, I would like to know what would be good practice as this project is really all about learning, and even though it won't be big enough to encounter performance issues from this I would like to consider them anyway. However, please note I am not interested in using message oriented middleware as a solution (I have experience with using MOM and I'm interested in considering other options excluding MOM if TCP sockets is a bad idea!).

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• (Abstract) Game engine design

  - by lukeluke

  I am writing a simple 2D game (for mobile platforms) for the first time. From an abstract point of view, i have the main player controlled by the human, the enemies, elments that will interact with the main player, other living elements that will be controlled by a simple AI (both enemies and non-enemies). The human player will be totally controlled by the player, the other actors will be controlled by AI. So i have a class CActor and a class CActorLogic to start with. I would define a CActor subclass CHero (the main player controlled with some input device). This class will probably implement some type of listener, in order to capture input events. The other players controlled by the AI will be probably a specific subclass of CActor (a subclass per-type, obviously). This seems to be reasonable. The CActor class should have a reference to a method of CActorLogic, that we will call something like CActorLogic::Advance() or similar. Actors should have a visual representation. I would introduce a CActorRepresentation class, with a method like Render() that will draw the actor (that is, the right frame of the right animation). Where to change the animation? Well, the actor logic method Advance() should take care of checking collisions and other things. I would like to discuss the design of a game engine (actors, entities, objects, messages, input handling, visualization of object states (that is, rendering, sound output and so on)) but not from a low level point of view, but from an high level point of view, like i have described above. My question is: is there any book/on line resource that will help me organize things (using an object oriented approach)? Thanks

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• Earmarks of a Professional PHP Programmer

  - by Scotty C.

  I'm a 19 year old student who really REALLY enjoys programming, and I'm hoping to glean from your years of experience here. At present, I'm studying PHP every chance I get, and have been for about 3 years, although I've never taken any formal classes. I'd love to some day be a programmer full time, and make a good career of it. My question to you is this: What do you consider to be the earmarks or traits of a professional programmer? Mainly in the field of PHP, but other, more generalized qualifications are also more than welcome, as I think PHP is more of a hobbyist language and may not be the language of choice in the eyes of potential employers. Please correct me if I'm wrong. Above all, I don't want to wast time on something that isn't worth while. I'm currently feeling pretty confident in my knowledge of PHP as a language, and I know that I could build just about anything I need and have it "work", but I feel sorely lacking in design concepts and code structure. I can even write object oriented code, but in my personal opinion, that isn't worth a hill of beans if it isn't organized well. For this reason, I bought Matt Zandstra's book "PHP Objects, Patterns, and Practice" and have been reading that a little every day. Anyway, I'm starting to digress a little here, so back to the original question. What advice would you give to an aspiring programmer who wants to make an impact in this field? Also, on a side note, I've been working on a project with a friend of mine that would give a fairly good idea of where I'm at coding wise. I'm gonna give a link, I don't want anyone to feel as though I'm pushing or spamming here, so don't click it if you don't want to. But if you are interested on giving some feedback there as well, you can see the code on github. I'm known as The Craw there. https://github.com/PureChat/PureChat--Beta-/tree/

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• Help required in adding new methods, properties into existing classes dynamically

  - by Bepenfriends

  Hi All, I am not sure whether it is possible to achieve this kind of implementation in Dot Net. Below are the information Currently we are on an application which is done in COM+, ASP, XSL, XML technologies. It is a multi tier architecture application in which COM+ acts as the BAL. The execution steps for any CRUD operation will be defined using a seperate UI which uses XML to store the information. BAL reads the XML and understands the execution steps which are defined and executes corresponding methods in DLL. Much like EDM we have our custom model (using XML) which determines which property of object is searchable, retrievable etc. Based on this information BAL constructs queries and calls procedures to get the data. In the current application both BAL and DAL are heavily customizable without doing any code change. the results will be transmitted to presentation layer in XML format which constructs the UI based on the data recieved. Now I am creating a migration project which deals with employee information. It is also going to follow the N Tier architecture in which the presentation layer communicates with BAL which connects to DAL to return the Data. Here is the problem, In our existing version we are handling every information as XML in its native form (no converstion of object etc), but in the migration project, Team is really interested in utilizing the OOP model of development where every information which is sent from BAL need to be converted to objects of its respective types (example employeeCollection, Address Collection etc). If we have the static number of data returned from BAL we can have a class which contains those nodes as properties and we can access the same. But in our case the data returned from our BAL need to be customized. How can we handle the customization in presentation layer which is converting the result to an Object. Below is an example of the XML returned <employees> <employee> <firstName>Employee 1 First Name</firstName> <lastName>Employee 1 Last Name</lastName> <addresses> <address> <addressType>1</addressType> <StreetName>Street name1</StreetName> <RegionName>Region name</RegionName> <address> <address> <addressType>2</addressType> <StreetName>Street name2</StreetName> <RegionName>Region name</RegionName> <address> <address> <addressType>3</addressType> <StreetName>Street name3</StreetName> <RegionName>Region name</RegionName> <address> <addresses> </employee> <employee> <firstName>Employee 2 First Name</firstName> <lastName>Employee 2 Last Name</lastName> <addresses> <address> <addressType>1</addressType> <StreetName>Street name1</StreetName> <RegionName>Region name</RegionName> <address> <address> <addressType>2</addressType> <StreetName>Street name2</StreetName> <RegionName>Region name</RegionName> <address> <addresses> </employee> </employees> If these are the only columns then i can write a class which is like public class Address{ public int AddressType {get;set;}; public string StreetName {get;set;}; public string RegionName {get;set;}; } public class Employee{ public string FirstName {get; set;} public string LastName {get; set;} public string AddressCollection {get; set;} } public class EmployeeCollection : List<Employee>{ public bool Add (Employee Data){ .... } } public class AddressCollection : List<Address>{ public bool Add (Address Data){ .... } } This class will be provided to customers and consultants as DLLs. We will not provide the source code for the same. Now when the consultants or customers does customization(example adding country to address and adding passport information object with employee object) they must be able to access those properties in these classes, but without source code they will not be able to do those modifications.which makes the application useless. Is there is any way to acomplish this in DotNet. I thought of using Anonymous classes but, the problem with Anonymous classes are we can not have methods in it. I am not sure how can i fit the collection objects (which will be inturn an anonymous class) Not sure about datagrid / user control binding etc. I also thought of using CODEDom to create classes runtime but not sure about the meory, performance issues. also the classes must be created only once and must use the same till there is another change. Kindly help me out in this problem. Any kind of help meterial/ cryptic code/ links will be helpful.

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• ArchBeat Link-o-Rama for 2012-09-25

  - by Bob Rhubart

  Oracle 11gR2 RAC on Software Defined Network (SDN) | Gilbert Stan "The SDN [software defined network] idea is to separate the control plane and the data plane in networking and to virtualize networking the same way we have virtualized servers," explains Gil Standen. "This is an idea whose time has come because VMs and vmotion have created all kinds of problems with how to tell networking equipment that a VM has moved and to preserve connectivity to VPN end points, preserve IP, etc." H/T to Oracle ACE Director Tim Hall for the recommendation. ServerSent-Events on WebLogic Server | Steve Buttons "The HTML5 ServerSent-Event model provides a mechanism to allow browser clients to establish a uni-directional communication path to a server, where the server is then able to push messages to the browser at any point in time," explains Steve "Buttso" Buttons. Focus on Architects and Architecture This handy guide for sessions and other activities at Oracle OpenWorld 2012 focuses on IT architecture in all its many facets and permutations. Operating System Set-up for WebLogic Server | Rene van Wijk Oracle ACE Rene van Wijk shows you how to set-up an operating system for WebLogic Server. "We will use VMware as our virtualization platform and use CentOS as the operating system," says van Wijk. "We end the post by showing how the operating system can be tuned when running a Java process such as WebLogic Server." Free eBook: Oracle SOA Suite - In the Customer's Words If you find yourself in the position of having to sell the idea of Service-oriented Architecture to business stakeholders this free e-book may come in very handy. Check out "Oracle SOA Suite: In the Customer's Words. (Registration / Oracle.com login required.) Thought for the Day "The first rule of any technology used in a business is that automation applied to an efficient operation will magnify the efficiency. The second is that automation applied to an inefficient operation will magnify the inefficiency." — Bill Gates Source: BrainyQuote.com

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• Synchronous vs. asynchronous for publish subscribe communication between JavaScript objects

  - by natlee75

  I implemented the publish subscribe pattern in a JavaScript module to be used by entirely client-side oriented JavaScript objects. This module has nothing to do with client-server communications in any way, shape or form. My question is whether it's better for the publish method in such a module to be synchronous or asynchronous, and why. As a very simplified example let's say I'm building a custom UI for an HTML5 video player widget: One of my modules is the "video" module that contains the VIDEO element and handles the various features and events associated with that element. This would probably have a namespace something like "widgets.player.video." Another is the "controls" module that has the various buttons - play, pause, volume, scrub, fullscreen, etc. This might have a namespace along the lines of "widgets.player.controls." These two modules are children of a parent "player" module ("widgets.player" ??), and as such would have no inherent knowledge of each other when instantiated as children of the "player" object. The "controls" elements would obviously need to be able to effect some changes on the video (click "Play" and the video should play), and vice versa (video's "timeUpdate" event fires and the visual display of the current time in the controls should update). I could tightly couple these modules and pass references to each other, but I'd rather take a more loosely coupled approach by setting up a pubsub type module that both can subscribe to and publish from. SO (thanks for bearing with me) in this kind of a scenario is there an advantage one way or another for synchronous publication versus asynchronous publication? I've seen some solutions posted online that allow for either/or with a boolean flag whereas others automatically do it asynchronously. I haven't personally seen an implementation that just automatically goes with synchronous publication... is this because there's no advantage to it? I know that I can accomplish this with features provided by jQuery, but it seems that there may be too much overhead involved here. The publish subscribe pattern can be implemented with relatively lightweight code designed specifically for this particular purpose so I'd rather go with that then a more general purpose eventing system like jQuery's (which I'll use for more general eventing needs :-).

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• Many-To-Many dimensional model

  - by Mevdiven

  Folks, I have a dimension table called DIM_FILE which holds information of the files we received from customers. Each file has detail records which constitutes my FACT table, CUST_DETAIL. In the main process, file is gone through several stages and each stage tags a status to it. Long in a short, I have many-to-many relationship. Any ideas around star schema dimensional modeling. A customer record only belong to a single file and a file can have multiple statuses. FACT ---- CustID FileID AmountDue DIM_FILE -------- FileID FileName DateReceived FILE_STATUS ----------- FileID StatusDateTime StatusCode

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• What advantages does developing applications for smartphones have over developing the same application as a web application?

  - by Alfredo O

  Let's take the Facebook application as an example. Why did they develop an application when the users could just access to their page and do the same? For me that represents more maintenance and more cost because for each feature added to the web application that feature will have to be added to the smartphone application as well. So why would I want to develop more than once (for each patform iOS, Android, etc) when I could just have one web application? What benefits do I get? The only one that comes to my mind is GPS feature. EDIT: My question is more oriented towards business applications that are going to be used only by some members of the company, it's not about selling the application (private use). So contrary to what some answers say about that by developing as a smartphone application it will benefit from more sells because of the "smartphone stores" for me this point is not important because the application is for private use. By developing the application as a web application it means that it can be accessed through smartphone browser and also in a PC (any capable browser), but developing as a native application would limit this to only some kind of smartphone so we would be limiting the use. On the other hand developing it as a web application means that in order to access the application an Internet connection must be available. So keeping this in mind how would you convince your boss to write the application for a given smartphone platform (iOS/Android) vs developing it as a web application?

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• Kids and programming: ScratchKara

  - by Mike Pagel

  Ever now and then I kept wondering how to share with my kids the excitement of creating something with your computer. Of course, today this is a bit more difficult, as they have seen 3D animation games and well-edited websites. I guess that's why they weren't all that hyped when I found my first computer model at our local recycling facilities (an 8-bit Laser VZ-200 with rubber keys). When I finally got it up and running with an old analog TV set they finally asked whether we could play soccer on it. Needless to say that my showing them how it remembers some BASIC commands and lists and executes them did not make any impression. So the question is for real: How do you get today's kids excited about programming? And just recently I looked again for environments that allow even young kids (mine are 7 and 9 years old now) to do something and have fun. Obviously any real, text-oriented programming language wouldn't work well. To cut it short: Something really nice was built by University of Oldenburg: ScratchKara. It is the perfect mixture of Kara, a simulation of a little ladybug and Scratch, an authoring environment from MIT. ScratchKara allows kids to initially simply explore how the bug moves and turns by pressing the action buttons, then move towards sequencing commands through drag & drop, and eventually end up building algorithms with procedures and functions. Even through it is built for kids and beginners, the environment comes with debugging and refactoring, which I found more than amazing. My kids love it and I have to admit I keep thinking about how to solve a bit more advanced problems with this language, which does not allow you to store any state information (other than your call stack). Yes, I am hooked, too... Once the language is understood you can then move to one of the original Kara versions, where you can define the bug's behavior through finite statemachines, Turing tables, Java and other textual languages. And from there, anything is possible.

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• Pixel plot method errors out without error message.

  - by sonny5

  // The following method blows up (big red x on screen) without generating error info. Any // ideas why? // MyPlot.PlotPixel(x, y, Color.BlueViolet, Grf); // runs if commented out // My goal is to draw a pixel on a form. Is there a way to increase the pixel size also? using System; using System.Drawing; using System.Drawing.Drawing2D; using System.Collections; using System.ComponentModel; using System.Windows.Forms; using System.Data; public class Plot : System.Windows.Forms.Form { private Size _ClientArea; //keeps the pixels info private double _Xspan; private double _Yspan; public Plot() { InitializeComponent(); } public Size ClientArea { set { _ClientArea = value; } } private void InitializeComponent() { this.AutoScaleBaseSize = new System.Drawing.Size(5, 13); this.ClientSize = new System.Drawing.Size(400, 300); this.Text="World Plot (world_plot.cs)"; this.Resize += new System.EventHandler(this.Form1_Resize); this.Paint += new System.Windows.Forms.PaintEventHandler(this.doLine); this.Paint += new System.Windows.Forms.PaintEventHandler(this.TransformPoints); // new this.Paint += new System.Windows.Forms.PaintEventHandler(this.DrawRectangleFloat); this.Paint += new System.Windows.Forms.PaintEventHandler(this.DrawWindow_Paint); } private void DrawWindow_Paint(object sender, PaintEventArgs e) { Graphics Grf = e.Graphics; pixPlot(Grf); } static void Main() { Application.Run(new Plot()); } private void doLine(object sender, System.Windows.Forms.PaintEventArgs e) { // no transforms done yet!!! Graphics g = e.Graphics; g.FillRectangle(Brushes.White, this.ClientRectangle); Pen p = new Pen(Color.Black); g.DrawLine(p, 0, 0, 100, 100); // draw DOWN in y, which is positive since no matrix called p.Dispose(); } public void PlotPixel(double X, double Y, Color C, Graphics G) { Bitmap bm = new Bitmap(1, 1); bm.SetPixel(0, 0, C); G.DrawImageUnscaled(bm, TX(X), TY(Y)); } private int TX(double X) //transform real coordinates to pixels for the X-axis { double w; w = _ClientArea.Width / _Xspan * X + _ClientArea.Width / 2; return Convert.ToInt32(w); } private int TY(double Y) //transform real coordinates to pixels for the Y-axis { double w; w = _ClientArea.Height / _Yspan * Y + _ClientArea.Height / 2; return Convert.ToInt32(w); } private void pixPlot(Graphics Grf) { Plot MyPlot = new Plot(); double x = 12.0; double y = 10.0; MyPlot.ClientArea = this.ClientSize; Console.WriteLine("x = {0}", x); Console.WriteLine("y = {0}", y); //MyPlot.PlotPixel(x, y, Color.BlueViolet, Grf); // blows up } private void DrawRectangleFloat(object sender, PaintEventArgs e) { // Create pen. Pen penBlu = new Pen(Color.Blue, 2); // Create location and size of rectangle. float x = 0.0F; float y = 0.0F; float width = 200.0F; float height = 200.0F; // translate DOWN by 200 pixels // Draw rectangle to screen. e.Graphics.DrawRectangle(penBlu, x, y, width, height); } private void TransformPoints(object sender, System.Windows.Forms.PaintEventArgs e) { // after transforms Graphics g = this.CreateGraphics(); Pen penGrn = new Pen(Color.Green, 3); Matrix myMatrix2 = new Matrix(1, 0, 0, -1, 0, 0); // flip Y axis with -1 g.Transform = myMatrix2; g.TranslateTransform(0, 200, MatrixOrder.Append); // translate DOWN the same distance as the rectangle... // ...so this will put it at lower left corner g.DrawLine(penGrn, 0, 0, 100, 90); // notice that y 90 is going UP } private void Form1_Resize(object sender, System.EventArgs e) { Invalidate(); } }

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• Develop and Use Applications with MySQL and PHP

  - by Antoinette O'Sullivan

  Want to develop and use applications with PHP and the MySQL database? Consider taking the MySQL and PHP: Developing Dynamic Web Applications training course. Before taking this course you should: Understand how HTML files are assembled Understand fundamental PHP syntax Have some programming experience (preferably PHP) Have some experience with relational databases Have some knowledge of Object-Oriented Programming This 4-day live, instructor-led course is perfect for developers who use PHP and MySQL to build and maintain their websites and who want to learn how PHP and MySQL can be used to rapidly prototype and deploy dynamic websites. You can take this course as a: Live-virtual event: Take this event from your own desk, no travel required, choosing from a selection of virtual events already on the schedule. In-class event: Travel to an education center to take this course. Below is a selection of events already on the schedule.  Location  Date  Delivery Language  Jakarta, Indonesia  3 December 2013 English   Rome, Italy  5 May 2014 Italian   Turin, Italy 17 March 2014  Italian   Warsaw, Poland 12 November 2013  Polish   Madrid, Spain  16 December 2013  Spanish  Tunis, Tunisia 17 March 2014  French For more information on the authentic MySQL curriculum, go to http://oracle.com/education/mysql.

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• Splitting a tetris game apart - where to put time-management?

  - by nightcracker

  I am creating a tetris game in C++ & SDL, and I'm trying to do it "good" by making it object-oriented and keeping scopes small. So far I have the following structure: A main with some lowlevel SDL set up and handling input A game class that keeps track of score and provides the interface for main (move block down, etc) A map class that keeps track of the current game field, which blocks are where. Used by the game class. A block class that consists of the current falling block, used by game. A renderer class abstracting low level SDL to a format where you render "tetris blocks". Used by map and block. Now I have a though time where to place the time-management of this game. For example, where should be decided when a block bumps the bottom of the screen how long it takes the current block locks in place and a new block spawns? I also have an other unrelated question, is there some place where you can find some standard data on tetris like standard score tables, rulesets, timings, etc?

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• Help needed on an SQL configuration problem.

  - by user321048

  I have been banging my head with this one more the two weeks, and still don't know what the problem is ( I can't narrow it down). The problem is the following. I have a solution with 3 project in it all written in c# and I with LINQ. One project is the main web site, the other is the data layer (communication with the database) and the third one is a custom little CMS. The problem is the following: On a hosting provider when I publish the site it all works perfectly, but this site was needed to be hosted on the client server so I needed to do that. But the problem is that I also needed to configure the client server, because they don't have an Administrator employed (I know, I know ;) ). For the first time I some how managed, to set it up but a problem appear. My main web site is working just as it suppose to be - it reads (communicates with) the database, but My CMS is not. It shows the first log in page, but after that when I try to log in it throws the following error: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.) Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Data.SqlClient.SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.) Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. Stack Trace: [SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.)] System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4846887 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194 System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, SqlConnection owningObject) +4860189 System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) +90 System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) +342 System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +221 System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +189 System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +185 System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +31 System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +433 System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +66 System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) +499 System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +65 System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +117 System.Data.SqlClient.SqlConnection.Open() +122 System.Data.Linq.SqlClient.SqlConnectionManager.UseConnection(IConnectionUser user) +44 System.Data.Linq.SqlClient.SqlProvider.get_IsSqlCe() +45 System.Data.Linq.SqlClient.SqlProvider.InitializeProviderMode() +20 System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query) +57 System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute(Expression expression) +23 System.Linq.Queryable.Count(IQueryable`1 source) +240 CMS.Security.UserProfile.LoginUser() in C:\Documents and Settings\Dimitar\Desktop\New Mepso Final 08_04\CMS\Classes\UserProfile.cs:132 CMS.Default.Login1_Authenticate(Object sender, AuthenticateEventArgs e) in C:\Documents and Settings\Dimitar\Desktop\New Mepso Final 08_04\CMS\Default.aspx.cs:37 System.Web.UI.WebControls.Login.OnAuthenticate(AuthenticateEventArgs e) +108 System.Web.UI.WebControls.Login.AttemptLogin() +115 System.Web.UI.WebControls.Login.OnBubbleEvent(Object source, EventArgs e) +101 System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37 System.Web.UI.WebControls.Button.OnCommand(CommandEventArgs e) +118 System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +166 System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10 System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13 System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565 Maybe this is a dumb question, but I cannot find the root of the problem, let alone the solution. So far I have tried the following: -setting time out on connection string to a higher value -configuration and after that turning off server firewall -checking the connection string over and over again (they are the same for all three projects and are saved in web.config) Important notes: I have tried executing the project from VS2008 with a connection string to the same database and the results are the same. That's why I think the problem is the SQL Server 2005 and not the IIS7. Any bit of information is more then welcomed.

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• What is the disadvantage of using abstract class as a database connectivity in zend framework 2 instead of service locator

  - by arslaan ejaz

  If I use database by creating adapter with drivers, initialize it in some abstract class and extend that abstract class to required model. Then use simple query statement. Like this: namespace My-Model\Model\DB; abstract class MysqliDB { protected $adapter; public function __construct(){ $this->adapter = new \Zend\Db\Adapter\Adapter(array( 'driver' => 'Mysqli', 'database' => 'my-database', 'username' => 'root', 'password' => '' )); } } And use abstract class of database like this in my models: class States extends DB\MysqliDB{ public function __construct(){ parent::__construct(); } protected $states = array(); public function select_all_states(){ $data = $this->adapter->query('select * from states'); foreach ($data->execute() as $row){ $this->states[] = $row; } return $this->states; } } I am new to zend framework, before i have experience of working in YII and Codeigniter. I like the object oriented in zend so i want to use it like this. And don't want to use it through service locater something like this: public function getServiceConfig(){ return array( 'factories' => array( 'addserver-mysqli' => new Model\MyAdapterFactory('addserver-mysqli'), 'loginDB' => function ($sm){ $adapter = $sm->get('addserver-mysqli'); return new LoginDB($adapter); } ) ); } In module. Am i Ok with this approach?

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• How to visualize code?

  - by gablin

  I've mostly only had to read my own code. As such, I've had no need to visualize the code as I already know how each and every class and module communicate with one another. But the few times I've had to read someone else's code - let us now assume we are talking about at least one larger module which contains several internal classes - I've almost always found myself wishing "This would have been so much easier to understand if I could just visualize it!" So what are the common methods or tools for enabling this? Which do you use, and why do you prefer them over the others? I've heard stuff like UML, module and class diagrams, but I imagine there are more. Furthermore, any of these is most likely better than anything I can devise on my own. EDIT: For those who answer with "Use pen and paper and just draw it": This isn't very helpful unless you explain this further. What exactly am I supposed to draw? A box for each class? Should I include the public methods? What about its fields? How should I draw connections that explain how one class uses another? What about modules? What if the language isn't object-oriented but functional or logical, or even just imperative (C, for instance)? What about global variables and functions? Is there an already-standardized way of drawing this, or do I need to think up of a method of my own? You get the drift.

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• SelfReferenceProperty vs. ListProperty Google App Engine

  - by John

  Hi All, I am experimenting with the Google App Engine and have a question. For the sake of simplicity, let's say my app is modeling a computer network (a fairly large corporate network with 10,000 nodes). I am trying to model my Node class as follows: class Node(db.Model): name = db.StringProperty() neighbors = db.SelfReferenceProperty() Let's suppose, for a minute, that I cannot use a ListProperty(). Based on my experiments to date, I can assign only a single entity to 'neighbors' - and I cannot use the "virtual" collection (node_set) to access the list of Node neighbors. So... my questions are: Does SelfReferenceProperty limit you to a single entity that you can reference? If I instead use a ListProperty, I believe I am limited to 5,000 keys, which I need to exceed. Thoughts? Thanks, John

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• WebCenter 11.1.1.8 Certified with E-Business Suite 12.2

  - by Steven Chan (Oracle Development)

  Oracle WebCenter Suite is an integrated suite of Fusion Middleware 11gR1 tools used to create web sites and portals using service-oriented architecture (SOA).  Applications adapters are also available. WebCenter Portal 11.1.1.8 is now certified with Oracle E-Business Suite Release 12.2.  This complements our existing certifications of WebCenter Portal 11.1.1.8 with EBS 12.0 and 12.1.  WebCenter Portal 11.1.1.8 is part of Oracle Fusion Middleware 11g Release 1 Version 11.1.1.8.0, also known as FMW 11gR1 Patchset 7.  Certified Platforms Oracle WebCenter Portal is certified to run on any operating system for which Oracle WebLogic Server 11g is certified. For information on operating systems supported by Oracle WebLogic Server 11g and Oracle WebCenter Portal, refer to the 'Oracle Fusion Middleware on WebLogic Server - System Certification' in the Oracle Fusion Middleware 11g Release 1 (11.1.1.x) Certification Matrix. Integration with Oracle WebCenter Portal involves components spanning several different suites of Oracle products. There are no restrictions on which platform any particular component may be installed so long as the platform is supported for that component. Migrating to Oracle WebCenterIf you're currently using Oracle Portal, you should be aware that Portal is now in maintenance mode.  Updates with bug fixes will continue to be produced, but you should consider migrating to Oracle WebCenter for ongoing new features. References Using WebCenter 11.1.1 with Oracle E-Business Suite Release 12.2 (Note 1332645.1) WebCenter Portal 11g Release 1 (11.1.1.8) Documentation Related Articles Oracle E-Business Suite 12.2 Now Available WebCenter Portal 11.1.1.8 Certified with E-Business Suite 12

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• deriving activity diagram-based GUIs and CRUD them with a DB?

  - by Xin Tanaka

  i received a big book full of processes. i was thinking about the end user (they will be lawyers) and decided the best GUI would be showing activity diagrams or business processes. It reminded me Quickbooks and how non-accountants can successfully use it and understand accounting processes. i began doing research before sending my project to a bunch of programmers: is there some open source solution? can i use MS Visio libraries? which UML tool is programable? what about Eclipse and its modeling tools? etc etc the key points here are: relationships between events, artifacts, actors, etc should be stored in a database. processes or steps in a process should be easily modified by updating the database do this sounds too crazy? (should I explain a bit more why it must be programmed this way?)

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• Which tool / technology: System management for databases and dependent services

  - by Filburt

  A follow-up on this system management question: Since I probably will not get much feedback on serverfault I'll give it a try here. My main concern is to reflect the dependencies between the databases, services ans tasks/jobs I'll have to manage. Besides considering Powershell, I even thought about using MSBuild because it would allow for modeling dependencies and reuse configuration targets. In other words: What technology should I use to develop a flexible solution that will allow me to stop service A, B and C on machine D in the right order and disable task E on machine F when taking down database X?

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• Silverlight IConvertible TypeConverter

  - by codingbloke

  I recently answered the following question on stackoverflow:  Silverlight 3 custom control: only ‘int’ as numeric type for a property? [e.g. long or int64 seems to break] I quickly knocked up the class ConvertibleTypeConverter<T> that I posted in the question (listed later here as well). Afterward I fully expected to find that of the usual clever “bods who blog” to have covered this probably with a better solution than I.  So far though I’ve not found one so I thought I’d blog it myself. The Problem Here is a classic gotcha I’ve seen asked more than once on stackoverflow :- public class MyClass {     public float SomeValue { get; set; } } <local:MyClass SomeValue="45.15" /> This fails with the error  “Failed to create a 'System.Single' from the text '45.15'”  and results in much premature hair loss.  Fortunately this is SL4, in SL3 the error message is almost meaningless.  So what gives, how can it be that this fails when we can see other very similar values parsing happily all over the place? It comes down the fact that the Xaml parser only handles a few of the primitive data types namely: bool, int, string and double.  Since the parser has no idea how to convert a string to a float we get the above error. The Solution The sensible solution is “use double not float” but lets not dwell on that, there has to be occasions where such an answer isn’t acceptable. In order to achieve parsing of other types we need an implementation of TypeConverter for the type of the property and then we need to use the TypeConverterAttribute to decorate the property .  As an example the Silverlight SDK provides one for DateTime the DateTimeTypeConverter (yes I know DateTime isn’t really a primitive). The following class will parse in Xaml:- public class MyClass {     [TypeConverter(typeof(DateTimeTypeConverter))]     public DateTime SomeValue {get; set; } } So far though we would need to create a TypeConverter for each primitive type we are using, what if I had the following mad class to support in Xaml:- public class StrangePrimitives {     public Boolean BooleanProp { get; set; }     public Byte ByteProp { get; set; }     public Char CharProp { get; set; }     public DateTime DateTimeProp { get; set; }     public Decimal DecimalProp { get; set; }     public Double DoubleProp { get; set; }     public Int16 Int16Prop { get; set; }     public Int32 Int32Prop { get; set; }     public Int64 Int64Prop { get; set; }     public SByte SByteProp { get; set; }     public Single SingleProp { get; set; }     public String StringProp { get; set; }     public UInt16 UInt16Prop { get; set; }     public UInt32 UInt32Prop { get; set; }     public UInt64 UInt64Prop { get; set; } } Then I want to fill an instance of StrangePrimitives with the following Xaml which of course fails. <local:StrangePrimitives x:Key="MyStrangePrimitives"                          BooleanProp="True"                          ByteProp="156"                          CharProp="A"                          DateTimeProp="06 Jun 2010"                          DecimalProp="123.56"                          DoubleProp="8372.937803"                          Int16Prop="16532"                          Int32Prop="73738248"                          Int64Prop="12345678909298"                          SByteProp="-123"                          SingleProp="39.0"                          StringProp="Hello, World!"                          UInt16Prop="40000"                          UInt32Prop="4294967295"                          UInt64Prop="18446744073709551615"      /> I got to thinking, though, one thing all these primitive types have in common is that they all implement IConvertible so it should be possible to write just one converter to handle them all.  Here it is:- The ConvertibleTypeConverter public class ConvertibleTypeConverter<T> : TypeConverter where T : IConvertible {     public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)     {         return sourceType.GetInterface("IConvertible", false) != null;     }     public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)     {         return destinationType.GetInterface("IConvertible", false) != null;     }     public override object ConvertFrom(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value)     {         return ((IConvertible)value).ToType(typeof(T), culture);     }     public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)     {         return ((IConvertible)value).ToType(destinationType, culture);     } } I won’t bore you with an explanation of how it works, it simply adapts one existing interface (the IConvertible) and exposes it as another (the TypeConverter).   With that in place the previous strange primitives class can be modified as:- public class StrangePrimitives {     public Boolean BooleanProp { get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<Byte>))]     public Byte ByteProp { get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<Char>))]     public Char CharProp { get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<DateTime>))]     public DateTime DateTimeProp { get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<Decimal>))]     public Decimal DecimalProp { get; set; }     public Double DoubleProp {get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<Int16>))]     public Int16 Int16Prop { get; set; }     public Int32 Int32Prop { get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<Int64>))]     public Int64 Int64Prop { get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<SByte>))]     public SByte SByteProp { get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<Single>))]     public Single SingleProp { get; set; }     public String StringProp { get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<UInt16>))]     public UInt16 UInt16Prop { get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<UInt32>))]     public UInt32 UInt32Prop { get; set; }     [TypeConverter(typeof(ConvertibleTypeConverter<UInt64>))]     public UInt64 UInt64Prop { get; set; } } This results in the previous Xaml parsing happily.  Now it seems such an obvious thing to do that one may wonder why such a class doesn’t already existing in Silverlight or at least in the SDK.   I would not be surprised if there were some very good reasons hence use the ConvertibleTypeConverter with caution.  It does seem to me to be a useful little class to have lying around in the toolbox for the odd occasion where it may be needed.

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• Query optimization using composite indexes

  - by xmarch

  Many times, during the process of creating a new Coherence application, developers do not pay attention to the way cache queries are constructed; they only check that these queries comply with functional specs. Later, performance testing shows that these perform poorly and it is then when developers start working on improvements until the non-functional performance requirements are met. This post describes the optimization process of a real-life scenario, where using a composite attribute index has brought a radical improvement in query execution times.  The execution times went down from 4 seconds to 2 milliseconds! E-commerce solution based on Oracle ATG – Endeca In the context of a new e-commerce solution based on Oracle ATG – Endeca, Oracle Coherence has been used to calculate and store SKU prices. In this architecture, a Coherence cache stores the final SKU prices used for Endeca baseline indexing. Each SKU price is calculated from a base SKU price and a series of calculations based on information from corporate global discounts. Corporate global discounts information is stored in an auxiliary Coherence cache with over 800.000 entries. In particular, to obtain each price the process needs to execute six queries over the global discount cache. After the implementation was finished, we discovered that the most expensive steps in the price calculation discount process were the global discounts cache query. This query has 10 parameters and is executed 6 times for each SKU price calculation. The steps taken to optimise this query are described below; Starting point Initial query was: String filter = "levelId = :iLevelId AND  salesCompanyId = :iSalesCompanyId AND salesChannelId = :iSalesChannelId "+ "AND departmentId = :iDepartmentId AND familyId = :iFamilyId AND brand = :iBrand AND manufacturer = :iManufacturer "+ "AND areaId = :iAreaId AND endDate >=  :iEndDate AND startDate <= :iStartDate"; Map<String, Object> params = new HashMap<String, Object>(10); // Fill all parameters. params.put("iLevelId", xxxx); // Executing filter. Filter globalDiscountsFilter = QueryHelper.createFilter(filter, params); NamedCache globalDiscountsCache = CacheFactory.getCache(CacheConstants.GLOBAL_DISCOUNTS_CACHE_NAME); Set applicableDiscounts = globalDiscountsCache.entrySet(globalDiscountsFilter); With the small dataset used for development the cache queries performed very well. However, when carrying out performance testing with a real-world sample size of 800,000 entries, each query execution was taking more than 4 seconds. First round of optimizations The first optimisation step was the creation of separate Coherence index for each of the 10 attributes used by the filter. This avoided object deserialization while executing the query. Each index was created as follows: globalDiscountsCache.addIndex(new ReflectionExtractor("getXXX" ) , false, null); After adding these indexes the query execution time was reduced to between 450 ms and 1s. However, these execution times were still not good enough.  Second round of optimizations In this optimisation phase a Coherence query explain plan was used to identify how many entires each index reduced the results set by, along with the cost in ms of executing that part of the query. Though the explain plan showed that all the indexes for the query were being used, it also showed that the ordering of the query parameters was "sub-optimal".  Parameters associated to object attributes with high-cardinality should appear at the beginning of the filter, or more specifically, the attributes that filters out the highest of number records should be placed at the beginning. But examining corporate global discount data we realized that depending on the values of the parameters used in the query the “good” order for the attributes was different. In particular, if the attributes brand and family had specific values it was more optimal to have a different query changing the order of the attributes. Ultimately, we ended up with three different optimal variants of the query that were used in its relevant cases: String filter = "brand = :iBrand AND familyId = :iFamilyId AND departmentId = :iDepartmentId AND levelId = :iLevelId "+ "AND manufacturer = :iManufacturer AND endDate >= :iEndDate AND salesCompanyId = :iSalesCompanyId "+ "AND areaId = :iAreaId AND salesChannelId = :iSalesChannelId AND startDate <= :iStartDate"; String filter = "familyId = :iFamilyId AND departmentId = :iDepartmentId AND levelId = :iLevelId AND brand = :iBrand "+ "AND manufacturer = :iManufacturer AND endDate >=  :iEndDate AND salesCompanyId = :iSalesCompanyId "+ "AND areaId = :iAreaId  AND salesChannelId = :iSalesChannelId AND startDate <= :iStartDate"; String filter = "brand = :iBrand AND departmentId = :iDepartmentId AND familyId = :iFamilyId AND levelId = :iLevelId "+ "AND manufacturer = :iManufacturer AND endDate >= :iEndDate AND salesCompanyId = :iSalesCompanyId "+ "AND areaId = :iAreaId AND salesChannelId = :iSalesChannelId AND startDate <= :iStartDate"; Using the appropriate query depending on the value of brand and family parameters the query execution time dropped to between 100 ms and 150 ms. But these these execution times were still not good enough and the solution was cumbersome. Third and last round of optimizations The third and final optimization was to introduce a composite index. However, this did mean that it was not possible to use the Coherence Query Language (CohQL), as composite indexes are not currently supporte in CohQL. As the original query had 8 parameters using EqualsFilter, 1 using GreaterEqualsFilter and 1 using LessEqualsFilter, the composite index was built for the 8 attributes using EqualsFilter. The final query had an EqualsFilter for the multiple extractor, a GreaterEqualsFilter and a LessEqualsFilter for the 2 remaining attributes.  All individual indexes were dropped except the ones being used for LessEqualsFilter and GreaterEqualsFilter. We were now running in an scenario with an 8-attributes composite filter and 2 single attribute filters. The composite index created was as follows: ValueExtractor[] ve = { new ReflectionExtractor("getSalesChannelId" ), new ReflectionExtractor("getLevelId" ),    new ReflectionExtractor("getAreaId" ), new ReflectionExtractor("getDepartmentId" ),    new ReflectionExtractor("getFamilyId" ), new ReflectionExtractor("getManufacturer" ),    new ReflectionExtractor("getBrand" ), new ReflectionExtractor("getSalesCompanyId" )}; MultiExtractor me = new MultiExtractor(ve); NamedCache globalDiscountsCache = CacheFactory.getCache(CacheConstants.GLOBAL_DISCOUNTS_CACHE_NAME); globalDiscountsCache.addIndex(me, false, null); And the final query was: ValueExtractor[] ve = { new ReflectionExtractor("getSalesChannelId" ), new ReflectionExtractor("getLevelId" ),    new ReflectionExtractor("getAreaId" ), new ReflectionExtractor("getDepartmentId" ),    new ReflectionExtractor("getFamilyId" ), new ReflectionExtractor("getManufacturer" ),    new ReflectionExtractor("getBrand" ), new ReflectionExtractor("getSalesCompanyId" )}; MultiExtractor me = new MultiExtractor(ve); // Fill composite parameters.String SalesCompanyId = xxxx;...AndFilter composite = new AndFilter(new EqualsFilter(me,                   Arrays.asList(iSalesChannelId, iLevelId, iAreaId, iDepartmentId, iFamilyId, iManufacturer, iBrand, SalesCompanyId)),                                     new GreaterEqualsFilter(new ReflectionExtractor("getEndDate" ), iEndDate)); AndFilter finalFilter = new AndFilter(composite, new LessEqualsFilter(new ReflectionExtractor("getStartDate" ), iStartDate)); NamedCache globalDiscountsCache = CacheFactory.getCache(CacheConstants.GLOBAL_DISCOUNTS_CACHE_NAME); Set applicableDiscounts = globalDiscountsCache.entrySet(finalFilter);      Using this composite index the query improved dramatically and the execution time dropped to between 2 ms and  4 ms.  These execution times completely met the non-functional performance requirements . It should be noticed than when using the composite index the order of the attributes inside the ValueExtractor was not relevant.

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