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Examining the Programming Model Extensions

Within IBM WebSphere Application Server version 6

Back in version 4 of IBM WebSphere Application Server (WAS), IBM released the Enterprise Edition of WAS. In version 5, IBM continued to release the Enterprise Edition (later renamed IBM WebSphere Business Integration Server Foundations in v5.1) with even more functionality. In version 5, the heart of the Enterprise Edition functionality was process choreographer, a Java 2 Enterprise Edition (J2EE)-based workflow engine. However, the Enterprise Edition also contains a slew of other technology sometimes referred to as the WAS Programming Model Extensions (PME). The goal of these programming model extensions is to provide solutions to problems that are difficult and sometimes impossible to solve using existing J2EE technology.

In WAS v5, customers needed to upgrade to the Enterprise Edition to benefit from WAS PMEs, leaving a large portion of WAS developers out of luck. However, in version 6 most of the PMEs have now been included in all editions of WAS. This means that all WebSphere version 6 users can benefit from these extensions without upgrading to a higher end workflow engine.

In this article, I will go over some of these WAS PMEs. I will discuss each PME in terms of the problem it solves. In addition, I'll talk about the work being done to add some of these extensions to future versions of the J2EE specification.

Overview of Extensions

In order to put some structure around this article, I am going to categorize the extensions by their problem space:
  • Multi-threading and scheduling extensions
  • Transactional enhancements and EJB entity bean extensions
  • Other extensions

Multi-threading and Scheduling

In this section, I am going to discuss some of the WAS PME features in the multi-threading and scheduling space.

Asynchronous Beans and CommonJ Work Manager
The J2EE platform shields developers from low-level system coding such as multithreaded programming. For that reason, there are many restrictions in the J2EE programming model when it comes to multithreading. For example, in J2EE 1.4, it is illegal to create your own Java threads in a J2EE container. WAS has no knowledge of these threads so it cannot propagate things such as a security context. In addition, because plain Java threads are random they cannot be managed by a thread pool; without someway to manage these threads, applications can lose control of machine resources. However, there are certain use cases that could benefit from the ability to do work asynchronously. Traditionally in J2EE such use cases are implemented with the Java Messaging Service (JMS). JMS forces you to define destinations, create messages, and code message driven beans to consume messages. JMS is a great platform for doing asynchronous work, especially for integration scenarios, but, in certain situations all a developer wants to do is accomplish concurrent processing. For example, you may have a use case where an application needs to retrieve data from two or three back end independent data sources. In order to speed up performance, the application could run these queries concurrently. With JMS, this is quite complex to write. However, WAS provides a framework (called asynchronous beans) of classes that allow programmers to have work executed on separate threads. In addition, asynchronous beans can also have activities performed in response to alarms or events. At the same time, it ensures that these activities are executed using the "logically correct" J2EE context. This model represents a very interesting compromise between the loosely coupled approach used with messaging and the tightly coupled approach of traditional J2EE programming that requires a single thread of execution.

WAS developers can create asynchronous beans instead of Java threads. Asynchronous beans allow a developer to code the work to be done on a separate thread. (It is important to note that because of work being done to standardize asynchronous beans, the asynchronous bean framework is also referred to as CommonJ WorkManager. This means that there are two APIs, one in com.ibm package referred to as asynchronous bean API, and the other in the commonj package referred to as CommonJ WorkManager API. For the purpose of this article we will refer to asynchronous beans and CommonJ WorkManager interchangeably; they are both configured the same way.) There are three types of asynchronous beans:

  • Work objects: Instances of classes that implement a special work interface. Essentially, the Work interface is the same as the Java runnable interface. However, Work instances can be submitted to a WorkManager (discussed below) for asynchronous execution. Unlike a plain runnable, Work inherits the J2EE context of their creator rather than the J2EE context of the thread pool where they actually run. Works allow a J2EE component to run operations in the background and asynchronously. The code that runs in the background behaves as if it were part of the J2EE application that instantiated the work.
  • Event listeners: These listeners are also asynchronous by nature. An application can create an event listener and subscribe to events. When the event occurs, the listener will be notified and will run the logic to handle the event. The problem with listeners in a J2EE container is that, since the listener runs asynchronously in its own thread, it won't be able to use the J2EE context of the subscriber. The asynchronous beans provide a generic notification framework that allows a J2EE component to subscribe a listener to generic events and have the listener execute its logic under the same J2EE context of the subscriber.
  • Timer listeners: (Not to be confused with EJB timers described later.) Special listeners that will be fired when a timer goes off. In the asynchronous bean framework, a timer can be created by a J2EE application. The listener will be invoked on a separate thread and it will inherit the same J2EE context as the timer creator. The code sample below shows an example of a timer.

    
    public class StockQuoteTimerListener implements TimerListener {
    	String context; 
    	String url;
    	  public StockQuoteTimerListener(String context, String url){
    	     this.context = context;
    	     This.url = url;
    	  }
    	  public void timerExpired(Timer timer) {
    	     System.out.println("Timer fired. Context ="+ 
    		 ((StockQuoteTimerListener)timer.getTimerListener()).getContext());
    
    	}
    	   public String getContext() {
    	    return context;
    	   }
    	}
    

    Timers are not persistent in WAS. If you need persistent services, the WAS scheduler or EJB timer service should be used. (In version 5, the Enterprise Edition provided alarms instead of timers. Timers are a replacement for alarms but the alarms are still supported.)

    As I mentioned, the J2EE context can flow from one J2EE component to another as long as they are called on the same thread. The asynchronous bean framework makes it possible to transfer all or some of the context to separate threads. The administrator can also configure which parts of the context are going to be transferred when a WorkManager is created. The following contexts can optionally be configured to propagate:

    • Security (J2EE security context)
    • Work area (another WAS PME explained later in this article)
    • Internationalization context (another WAS PME explained later in this article)
    • Application profiling definitions (another WAS PME explained later in this article)
    In addition, the java:comp/env local namespace is always passed along with asynchronous beans.

    Due to the asynchronous nature of this programming model, transactional contexts are not passed to the asynchronous beans. The asynchronous beans get their own local transaction, or they can start global transactions if XA resources are involved.

    Asynchronous beans should stay away from caching connections. They can cache connection factories and then get a connection, use it, and release it at the end of the asynchronous execution. That way connection pooling is used correctly.

    The WorkManager is the heart of the asynchronous bean framework. A WorkManager is essentially a thread pool. It runs Work instances asynchronously and controls the transfer of J2EE contexts to those threads. The WorkManager is the anchor point that allows developers to create asynchronous beans. Applications will look up the WorkManagers using JNDI. Once an application has obtained a WorkManager, it can use it, for example, to submit Work instances. The WorkManager returns a WorkItem to the application, which can use it to monitor the progress of the work. Applications can define resource references to work managers.

    For timers, timer managers are configured on the server much the same way as work managers (see Figure 1).

    The asynchronous bean framework is the basis for two new JSRs which have been submitted jointly by IBM and BEA. These are JSR 236 (Timers for Application Servers) and JSR 237 (Work Managers for Application Servers).

    For further information on asynchronous beans, see the following link: http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.nd.doc/info/ae/ae/welc6tech_asb.html.

    Scheduler Service
    Prior to J2EE 1.4, the J2EE specification defined no solution for scheduling. Applications that required scheduling to run batch jobs or scheduled events needed to do so outside the application server. In version 5, WAS introduced the scheduler service in the Enterprise Edition. Applications could now write batch jobs and scheduled events that ran inside an application server. Batch applications could now benefit from container managed transactions and J2EE security. A developer just had to provide a stateless session bean class and use the provided home and remote interface. A scheduler would then be configured administratively. Tasks could be scheduled using the scheduler API either in Java code or wsadmin. The scheduler service continues to function in WAS Application Server version 6. Figure 2 shows the administrative console screen for creating a scheduler.

    Applications can then treat the scheduler as a resource and create tasks as shown:

    	
    //lookup Scheduler as a Resource
    context = new InitialContext();
    
    Object schedulerObj =
    context.lookup("java:comp/
    env/scheduler/MyScheduler");
    
    scheduler = (Scheduler) schedulerObj;
    
    //Lookup Task Handler as an EJB
    Object taskHandlerObj = context.lookup("java:comp/
    env/ejb/StockTickerPublisher");
    taskHandlerHome =
    (TaskHandlerHome) PortableRemoteObject.narrow(
    taskHandlerObj,
    TaskHandlerHome.class);
    //Create Task
    taskInfo = scheduler.createBeanTaskInfo();
    //Associate TaskHandler with Task
    taskInfo.setTaskHandler(taskHandlerHome);
    taskInfo.setStartTimeInterval(startInterval
    + "minutes");
    taskInfo.setRepeatInterval(repeatInterval + "minutes");
    taskInfo.setNumberOfRepeats(repeats);
    taskInfo.setName(taskName);
    //Create Task in Scheduler
    TaskStatus status = scheduler.create(taskInfo);
    

    WAS provides the home and remote interface for the task handler object. Developers only need to provide a bean class with a special process method:

    
    //Example task handler
    public void process(TaskStatus taskStatus)
    {
    	try
    	{
    		publisherBO.publishStockTicker();
    	}
    	catch (StockException e)
    	{
    		throw new EJBException(e.getLocalizedMessage(),e);
    	}
    }
    

    In J2EE 1.4, the EJB timer service is introduced to the specification. The EJB timer service allows any EJB component that implements the TimerObject interface to be called by some scheduling component. Any EJB type can be used (session bean, entity bean, or message driven bean) as a timed object. The timer service also defines a standard interface called TimerService for scheduling events. In version 6, the EJB timed objects is a special type of WAS TaskHandler. So the EJB timed components build upon the same scheduling infrastructure provided in version 6. By default, an internal scheduler instance is used to manage those tasks, and they are persisted to a Cloudscape database associated with the server process.

    The EJB timer service can be configured on the desired server (see Figure 3).

    You can choose to use the default pre-configured scheduler or your own (see Figure 4).

    Any EJB type can implement the TimedObject interface and implement the ejbTimeout() method:

    
    import javax.ejb.Timer;
    import javax.ejb.TimedObject;
    import javax.ejb.TimerService;
    
    public class MyBean implements SessionBean, TimedObject {
    
      // This method is called by the EJB container upon Timer expiration.
      public void ejbTimeout(Timer theTimer) {
    
        // Any code typically placed in an EJB method can be placed here.
    
         String whyWasICalled = (String) Timer.getInfo():
         System.out.println("I was called because of"+ whyWasICalled);
      } // end of method ejbTimeout
    

    Keep in mind that you cannot use the scheduler API to schedule tasks for EJB-based timers or use the TimerService API to configure WAS TaskHandlers.

    For further information on the scheduler service, see the following URL: http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.express.doc/info/exp/ae/welc6tech_sch.html.

    Transactional Enhancements and EJB Entity Bean Extension

    In this section I will discuss some extensions that deal with transactions, such as single phase resources inside an XA transaction. I will also discuss some extensions to entity beans, such as dynamic query and application profiles.

    Last Participant Support
    One of the major motivations behind J2EE application servers is the ability to provide enterprise applications with a transaction manager that can coordinate transactions across multiple resources. J2EE application server can coordinate transactions across multiple resources as long as they support the XA specification. In a perfect world, all back end resources would have support for XA. However, since this is not a perfect world, this is not the case. There are some back end systems that do not support XA. For example, distributed platforms often communicate with legacy systems that do not support XA, such as IBM? CICS? systems.

    Ordinarily, all participants in a two-phase commit process must be two-phase commit-capable. With the last participant support (LPS), you can use a single one-phase commit (1PC)-capable resource with any number of two-phase commit (2PC)-capable resources in the same global transaction. The global transaction commit processing still takes place in two phases. In phase one, all the two-phase commit resources are prepared using the two-phase commit protocol. During phase two, the one-phase commit resource is called to commit first if all the two-phase resources successfully prepared. This way, if the 1PC resource fails, WAS can simply roll back the other resources. On the other hand, if the 1PC commit resource succeeds, WAS can commit the remaining resources. Figure 5 illustrates the process.

    Keep in mind that LPS is not a complete substitute for using a resource that fully supports 2PC. It should only be used when you want to commit a one-phase capable resource (that has no 2PC support) with other 2PC resources and you want to get as close to 2PC as possible. LPS introduces a hazard of a mixed commit result because 1PC resources can't completely participate in the 2PC protocol. For example, if the WAS doesn't get a response from the 1PC resource, it has no way of knowing the status. Thus, WAS can't know whether the 1PC resource committed or not and thus does not know how to proceed. In this case, manual intervention will be required to resolve the state of the data in the 1PC resource. No special programming is needed to use LPS; it only needs to be enabled using WebSphere Application Server administration.

    For more information on last participant support, see http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.express.doc/info/exp/lao/ref/rla_rlinks.html.

    Activity Sessions
    With LPS, you can only have at most one nonphase capable resource in your XA transaction. However, if you have multiple one-phase capable resources and you need some level of coordination between them, WAS provides the activity session service. Activity sessions extend the JTA transaction model by providing an alternative unit of work to deal with 1PC. Activity sessions provide several features:

    1.  Client-side demarcation of and coordination of multiple one-phase units of work: The activity session service captures the commit operations of each local and global transaction and upholds them. At the end of the activity session, the container will go back and commit (or roll back) each individual transaction. Keep in mind that the activity session, like LPS, is no substitute for two-phase commitment control, when it comes to data integrity. An activity session may result in a mixed outcome, if some of the single phase resources successfully get committed before another resource fails to commit. In that case, the activity session service will allow the programmer to retrieve the list of resources that were committed and those whose state is uncertain.
    2.  Distributed context distribution using the OMG activity service: In order to support a declarative model, activity sessions define propagation of activity sessions from one component to another. The activity session context propagates according to the standards defined by the OMG activity service. See JSR 95 description at www.jcp.org/en/jsr/detail?id=95.
    3.  Extensions to local transaction support: WebSphere Application Server supports the notion of local transaction containment (LTC), which allowed the container to deal with unresolved resource manager local transactions and the resources associated with them. An LTC is created by default when an XA transaction is absent. Activity sessions can be used to extend the life of an LTC.
    4.  Extended entity bean life cycle support: The entity EJB can then be configured to be activated at the activity session boundaries, rather than at the transaction boundaries. The container will then keep the entity EJB active for the duration of the activity session - which corresponds to the duration of the unit of work - but no global transaction is needed to achieve this result. We often refer to this scenario as the "Commit option C plus" in that it offers a nice compromise between option C and option A by allowing the client to closely control the activation boundaries without resorting to XA transactions all the time.
    5.  Association of activity session with HttpSession to scope contexts to the life cycle of HTTP clients: You can scope an activity session to an HTTP session to help scope the life of activity sessions in Web applications. This is a powerful concept that allows you to mimic user level transactions which are made up of multiple resource transactions. Combined with the extended dntity bean life cycle support, you can interact with entity bean data without them reloading for the life of an activity session. This technique makes it possible to implement some long-running transaction semantics.

    There are two approaches to implementing activity sessions in your applications: the declarative (or container-managed) approach and the programmatic (or bean managed) approach. The programming model for activity sessions and the terminology which relates to the activity session service closely resemble the standard definitions that apply to transaction management, making it simple for a J2EE programmer to become familiar with the activity session semantics. Activity session scopes can be defined either through declarations that apply to EJB methods invocations (in a very similar way as for declarative demarcation of transactions) or servlets - or programmatically, using the UserActivitySession APIs - which are semantically very similar to the standard UserTransaction APIs.

    Figure 6 shows an example of a scenario. Here you have two different entity beans each mapped to a different 1PC resource. The EJB methods are demarcated much like you would regular transactions only using ActivityService demarcations.

    Activity sessions are not just bound to local resources. They can even be used to group multiple 2PC.

    Activity sessions are being worked on for future versions of J2EE as JSR 95: J2EE TM Activity Service for Extended Transactions (URL).

    For more information on the activity service, see: http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.express.doc/info/exp/ae/welc6tech_as.html.

    Other Entity Bean Enhancements
    Websphere Application Server v6 adds some enhancements to entity beans:

    1.  Dynamic query support: The current EJB 2.1 specification only allows you to define EJB QL statically in the EJB deployment descriptor. However, there are times when an application needs to construct a query dynamically. The dynamic query service provides an API you can use to pass EJB QL at runtime. The dynamic query service is automatically deployed on WAS as a stateless session bean with a local and remote interface. Dynamic queries is being worked on as part of EJB 3.0.

    For more information on dynamic query, see: http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.express.doc/info/exp/ae/welc6tech_que.html.
    2.  Extensions to EJB QL: WAS version 6 provides several extensions to EJB QL to meet real application requirements. Some examples include: querying business bean methods, dependent values, and multiple element selects.
    3.  Application profiles: WAS uses the notion of access intents on entity beans to define things such as isolation level and lazy loading of collection-based data. In WASv5, an entity bean method could only be assigned one access intent. If an entity bean needed to be accessed by different session beans that had different access intent requirements, you needed to define multiple methods that access the same data or sometimes even create new entity beans mapped to the same data with different access intents. Application profiles allow me to create multiple access intents on the same entity bean method and mark the calling session beans with a particular task. Based on the container task of the session bean, the entity bean will use the correct access intent for the particular use case. This allows entity beans to be more reusable across various data access requirements.

    For more information on application profiles, see: http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.express.doc/info/exp/ae/welc6tech_appprof.html.

    Other PMEs

    We will briefly review some more WAS 6 PMEs and provide links where you can find more information.

    WorkArea Service
    The J2EE specification defines a component style of development. Components share data by passing information through well defined interfaces. Certain information, however, gets passed automatically. For example, transactional components such as Enterprise JavaBean components pass a transactional context to each other. Another example is a servlet that can propagate a security context to a stateless session bean. Developers do not have to pass transactional or security handles from one component to another, even when calling remote session beans. J2EE application servers pass this information along transparently. However, most other data traditionally needs to be passed through interfaces. Certain data, however, could benefit from automatic propagation. Usually any data that is needed by many components (for example, profile data about a user) is a good candidate for automatic propagation. Rather than populating every interface with the same information, it would be nice if you could propagate this frequently used information using some J2EE context.

    WAS version 6 provides this function through the WorkArea service. By using a simple API, components can pass context information from component to component without passing it directly through programmatic interface. The WorkArea service will propagate to local components using thread local storage and it will pass data to remote components through IIOP. Work areas can be nested as well to allow flexibility of layering your code correctly.

    A client component can create a UserWork area:

    	
    //Lookup UserWorkArea
    UserWorkArea workArea =  (UserWorkArea) ctx.lookup("java:comp/websphere/UserWorkArea");
    
    //create workArea
    workArea.begin("Profile");
    workArea.set("Name","Luke Skywalker");
    workArea.set("Age",new Integer(28));
    
    //call component
    myEJB.callService(params);
    
    //complete workArea
    workArea.complete();
    

    The target component can then access the UserWorkarea to obtain the information.

    
    void callService() throws SomeException
    {
    InitialContext ctx = new InitialContext();
    	//lookup WorkArea
    UserWorkArea workArea =
    (UserWorkArea) ctx.lookup("java:comp/websphere/UserWorkArea");
    
    	//Access Data
    System.out.println("Work Area");
    	System.out.println("Name : " + workArea.get("Name"));
    	System.out.println("Age : " + workArea.get("Age"));
    }
    

    IBM is leading JSR 149 for adding WorkArea support to the J2EE specification.

    You can find more information about the WorkArea service at: http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.base.doc/info/aes/ae/welc6tech_wa.html.

    Internationalization Service
    Many applications require Internationalization(i18n) support. In most cases, developers can rely on using resource bundles to display data in different languages or regions. However, some i18n requirements are more than just displaying data; applications may need to alter business logic depending on the locale of the user. For example, based on what country you logged in on, an application may need to provide different tax rules. In order to be able to do this, an application would need to get some information about the locale or time zone of the user to properly handle the logic correctly. One could use the WorkArea service to pass i18n, however, having i18n data passed in a special way can benefit greatly. Consider another case where a company needs to develop an internationalized application that is meant to be deployed in various countries. Depending in which country the application is deployed, applications require certain portions of the application to run logic differently. Rather than maintaining different code bases, the i18n service can also be used to determine the locale of the server. This allows applications to deal with both their local i18n context and the caller's i18n context separately. The i18n service allows applications to access both the caller's i18n information as well as the local servers transparently.

    The i18n service in WAS 6 allows applications to access the i18n context of the caller:

    
    UserInternationalization i18nService = (UserInternationalization) ctx.lookup("java:comp/websphere/UserInternationalization");
    
    Internationalization callerI18n = i18nService.getCallerInternationalization();
    

    The i18n service also allows applications to access the i18n context of the running environment:

    
    UserInternationalization i18nService =
    (UserInternationalization) ctx.lookup(
    "java:comp/websphere/UserInternationalization");
    
    InvocationInternationalization invI18n =
    i18nService.getInvocationInternationalization();
    

    IBM is working on standardizing the i18n service through JSR 150.

    More information can be found at: http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.base.doc/info/aes/ae/welc6tech_in.html.

    Object Pools
    J2EE application servers provide pooling for Enterprise JavaBean components as well as resources such as JDBC connections. However, there are times when applications need to pool plain Java objects. Many times developers spend time developing their own object pools or invest in some third party library. WAS provides an object pool that can pool any arbitrary set of objects. The object pool can be configured through the WAS administrative console or through any supported WAS administrative client.

    More information about object pools can be found at: http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.base.doc/info/aes/ae/welc6tech_objp.html.

    Startup Beans
    Most applications require some sort of initialization. For example, an application may need to cache some read only data for fast access. This data can be initialized at start up. In the Web container, this can be done by marking a servlet for start up in the web.xml file. However, in the EJB container, start up logic can be challenging. The J2EE specification does not define a way to handle start up logic in the EJB container. WAS provides startup beans that can be used to accomplish start up logic in the EJB container.

    More information can be found about startup beans at: http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.base.doc/info/aes/ae/welc6tech_sub.html.

    Dynamic Cache
    The dynamic cache service is a whole caching infrastructure. It is a large topic and requires its own paper. My book (referenced at the end of this article) has a whole chapter on this topic. In short, the dynamic cache service improves performance by caching the output of servlets, commands, Web services, and JSP files. Dynamic caching features include replication of cache entries, cache disk offload, Edge-Side Include caching, Web services, and external caching.

    More information on dynamic cache service can be found at: http://publib.boulder.ibm.com/infocenter/ws60help/index.jsp?topic=/ com.ibm.websphere.base.doc/info/aes/ae/welc6tech_dyn.html.

    Conclusion

    This article provided an overview of many of the WAS programming model extensions. There are certainly other extensions not addressed in this article. For example, there are more extensions in the area of SOA, such as the Web Service Gateway or Service Data Objects (SDO). This article tries to provide the PMEs that were previously only available in the Enterprise Edition (WBI SF) of WAS. Now, all WebSphere Application Server customers can use these enterprise class PMEs to fulfill their enterprise requirements.

    Acknowledgments

    Thanks to Billy Newport, Chris Johnson, and Bruce Clay for reviewing this document.

    References

  • IBM WebSphere: Deployment and Advanced Configuration (by Roland Barcia, Tom Alcott, Bill Hines, and Keys Botzum) www.amazon.com/exec/obidos/tg/detail/-/0131468626/qid=1106108458/ sr=1-1/ref=sr_1_1/103-0795483-2226208?v=glance&s=books
  • Migrating WebLogic Startup Code to WebSphere Application Server www-106.ibm.com/developerworks/websphere/library/ techarticles/0401_beaton/0401_beaton.html
  • Specifications: service data objects, work managers, and timers www-128.ibm.com/developerworks/java/library/j-commonj-sdowmt/index.html
  • Introduction to service sata objects: www-128.ibm.com/developerworks/java/library/j-sdo/index.html
  • Static and dynamic caching in WebSphere Application Server: www-128.ibm.com/developerworks/websphere/techjournal/0405_hines/0405_hines.html
  • More Stories By Roland Barcia

    Roland Barcia is a consulting IT specialist for IBM Software Services for WebSphere in the New York/New Jersey Metro area. He is the author of one of the most popular article series on the developerWorks WebSphere site, www-106.ibm.com/developerworks/websphere/techjournal/0401_barcia/barcia.html, and is also a coauthor of IBM WebSphere: Deployment and Advanced Configuration. You can find more information about him at http://web.njit.edu/~rb54

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    Most Recent Comments
    Simon Birch 04/07/08 01:16:28 AM EDT

    Good article, but is the statement, "it is illegal to create your own threads in a J2EE container", 100% correct? I am not saying that it's not - I would just like to know the answer. I have heard many people say that J2EE applications should not spawn threads, but I can not find any documentation stating this in the Java 2 Platform Enterprise Edition Specification. The Enterprise JavaBeans Specification, Version 2.1, does explicitly say that an enterprise bean must not attempt to manage threads. So, this would lead me to believe that a J2EE application can spawn threads.

    Simon Birch 04/07/08 01:15:35 AM EDT

    Good article, but is the statement, "it is illegal to create your own threads in a J2EE container", 100% correct? I am not saying that it's not - I would just like to know the answer. I have heard many people say that J2EE applications should not spawn threads, but I can not find any documentation stating this in the Java 2 Platform Enterprise Edition Specification. The Enterprise JavaBeans Specification, Version 2.1, does explicitly say that an enterprise bean must not attempt to manage threads. So, this would lead me to believe that a J2EE application can spawn threads.

    Also, if you must have a reason why threads would be used, then imagine that ten calls must be made to a server to retrieve values that are not dependent on each other. It would make sense to do these ten calls asynchronously.

    @ThingsExpo Stories
    Growth hacking is common for startups to make unheard-of progress in building their business. Career Hacks can help Geek Girls and those who support them (yes, that's you too, Dad!) to excel in this typically male-dominated world. Get ready to learn the facts: Is there a bias against women in the tech / developer communities? Why are women 50% of the workforce, but hold only 24% of the STEM or IT positions? Some beginnings of what to do about it! In her Opening Keynote at 16th Cloud Expo, Sandy Carter, IBM General Manager Cloud Ecosystem and Developers, and a Social Business Evangelist, d...
    Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at @ThingsExpo, James Kirkland, Red Hat's Chief Architect for the Internet of Things and Intelligent Systems, described how to revolutionize your archit...
    The Internet of Things is not only adding billions of sensors and billions of terabytes to the Internet. It is also forcing a fundamental change in the way we envision Information Technology. For the first time, more data is being created by devices at the edge of the Internet rather than from centralized systems. What does this mean for today's IT professional? In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists addressed this very serious issue of profound change in the industry.
    Discussions about cloud computing are evolving into discussions about enterprise IT in general. As enterprises increasingly migrate toward their own unique clouds, new issues such as the use of containers and microservices emerge to keep things interesting. In this Power Panel at 16th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists addressed the state of cloud computing today, and what enterprise IT professionals need to know about how the latest topics and trends affect their organization.
    For IoT to grow as quickly as analyst firms’ project, a lot is going to fall on developers to quickly bring applications to market. But the lack of a standard development platform threatens to slow growth and make application development more time consuming and costly, much like we’ve seen in the mobile space. In his session at @ThingsExpo, Mike Weiner, Product Manager of the Omega DevCloud with KORE Telematics Inc., discussed the evolving requirements for developers as IoT matures and conducted a live demonstration of how quickly application development can happen when the need to comply wit...
    The Internet of Everything (IoE) brings together people, process, data and things to make networked connections more relevant and valuable than ever before – transforming information into knowledge and knowledge into wisdom. IoE creates new capabilities, richer experiences, and unprecedented opportunities to improve business and government operations, decision making and mission support capabilities.
    There will be 150 billion connected devices by 2020. New digital businesses have already disrupted value chains across every industry. APIs are at the center of the digital business. You need to understand what assets you have that can be exposed digitally, what their digital value chain is, and how to create an effective business model around that value chain to compete in this economy. No enterprise can be complacent and not engage in the digital economy. Learn how to be the disruptor and not the disruptee.
    SYS-CON Events announced today that HPM Networks will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. For 20 years, HPM Networks has been integrating technology solutions that solve complex business challenges. HPM Networks has designed solutions for both SMB and enterprise customers throughout the San Francisco Bay Area.
    Akana has released Envision, an enhanced API analytics platform that helps enterprises mine critical insights across their digital eco-systems, understand their customers and partners and offer value-added personalized services. “In today’s digital economy, data-driven insights are proving to be a key differentiator for businesses. Understanding the data that is being tunneled through their APIs and how it can be used to optimize their business and operations is of paramount importance,” said Alistair Farquharson, CTO of Akana.
    Business as usual for IT is evolving into a "Make or Buy" decision on a service-by-service conversation with input from the LOBs. How does your organization move forward with cloud? In his general session at 16th Cloud Expo, Paul Maravei, Regional Sales Manager, Hybrid Cloud and Managed Services at Cisco, discusses how Cisco and its partners offer a market-leading portfolio and ecosystem of cloud infrastructure and application services that allow you to uniquely and securely combine cloud business applications and services across multiple cloud delivery models.
    The enterprise market will drive IoT device adoption over the next five years. In his session at @ThingsExpo, John Greenough, an analyst at BI Intelligence, division of Business Insider, analyzed how companies will adopt IoT products and the associated cost of adopting those products. John Greenough is the lead analyst covering the Internet of Things for BI Intelligence- Business Insider’s paid research service. Numerous IoT companies have cited his analysis of the IoT. Prior to joining BI Intelligence, he worked analyzing bank technology for Corporate Insight and The Clearing House Payment...
    It is one thing to build single industrial IoT applications, but what will it take to build the Smart Cities and truly society-changing applications of the future? The technology won’t be the problem, it will be the number of parties that need to work together and be aligned in their motivation to succeed. In his session at @ThingsExpo, Jason Mondanaro, Director, Product Management at Metanga, discussed how you can plan to cooperate, partner, and form lasting all-star teams to change the world and it starts with business models and monetization strategies.
    Converging digital disruptions is creating a major sea change - Cisco calls this the Internet of Everything (IoE). IoE is the network connection of People, Process, Data and Things, fueled by Cloud, Mobile, Social, Analytics and Security, and it represents a $19Trillion value-at-stake over the next 10 years. In her keynote at @ThingsExpo, Manjula Talreja, VP of Cisco Consulting Services, discussed IoE and the enormous opportunities it provides to public and private firms alike. She will share what businesses must do to thrive in the IoE economy, citing examples from several industry sectors.
    In his keynote at 16th Cloud Expo, Rodney Rogers, CEO of Virtustream, discussed the evolution of the company from inception to its recent acquisition by EMC – including personal insights, lessons learned (and some WTF moments) along the way. Learn how Virtustream’s unique approach of combining the economics and elasticity of the consumer cloud model with proper performance, application automation and security into a platform became a breakout success with enterprise customers and a natural fit for the EMC Federation.
    "Optimal Design is a technology integration and product development firm that specializes in connecting devices to the cloud," stated Joe Wascow, Co-Founder & CMO of Optimal Design, in this SYS-CON.tv interview at @ThingsExpo, held June 9-11, 2015, at the Javits Center in New York City.
    SYS-CON Events announced today that CommVault has been named “Bronze Sponsor” of SYS-CON's 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. A singular vision – a belief in a better way to address current and future data management needs – guides CommVault in the development of Singular Information Management® solutions for high-performance data protection, universal availability and simplified management of data on complex storage networks. CommVault's exclusive single-platform architecture gives companies unp...
    Electric Cloud and Arynga have announced a product integration partnership that will bring Continuous Delivery solutions to the automotive Internet-of-Things (IoT) market. The joint solution will help automotive manufacturers, OEMs and system integrators adopt DevOps automation and Continuous Delivery practices that reduce software build and release cycle times within the complex and specific parameters of embedded and IoT software systems.
    "ciqada is a combined platform of hardware modules and server products that lets people take their existing devices or new devices and lets them be accessible over the Internet for their users," noted Geoff Engelstein of ciqada, a division of Mars International, in this SYS-CON.tv interview at @ThingsExpo, held June 9-11, 2015, at the Javits Center in New York City.
    Internet of Things is moving from being a hype to a reality. Experts estimate that internet connected cars will grow to 152 million, while over 100 million internet connected wireless light bulbs and lamps will be operational by 2020. These and many other intriguing statistics highlight the importance of Internet powered devices and how market penetration is going to multiply many times over in the next few years.
    SYS-CON Events announced today that Dyn, the worldwide leader in Internet Performance, will exhibit at SYS-CON's 17th International Cloud Expo®, which will take place on November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Dyn is a cloud-based Internet Performance company. Dyn helps companies monitor, control, and optimize online infrastructure for an exceptional end-user experience. Through a world-class network and unrivaled, objective intelligence into Internet conditions, Dyn ensures traffic gets delivered faster, safer, and more reliably than ever.