Close any open resources, like database connections b. All non-transient, non-serializable fields except some special types should be set to null. All transient fields should be set to null d. Make all database connection reference fields transient e. All primitive type fields should be set to null Choices A, B and D are correct.
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How can I run multiple instances of the same servlet class in the same WebLogic Server instance? If you want to run multiple instances, your servlet will have to implement the SingleThreadModel interface. An instance of a class that implements the SingleThreadModel interface is guaranteed not to be invoked by multiple threads simultaneously. Multiple instances of a SingleThreadModel interface are used to service simultaneous requests, each running in a single thread.
When designing your servlet, consider how you use shared resources outside of the servlet class such as file and database access. Because there are multiple instances of servlets that are identical, and may use exactly the same resources, there are still synchronization and sharing issues that must be resolved, even if you do implement the SingleThreadModel interface. It can, however, still be used as a way to identify the XML document.
In case of a MDB, developer needs to create a MessageListener class that utilizes a server-wide session pool. Choices B and C are correct. As with standard JMS message consumers, message-driven beans receive messages from a JMS Queue or Topic, and perform business logic based on the message contents.
EJB deployers create listeners to a Queue or Topic at deployment time, and WebLogic Server automatically creates and removes message-driven bean instances as needed to process incoming messages. Because message-driven beans are implemented as EJBs, they benefit from several key services that are not available to standard JMS consumers.
Using a single message-driven bean class, WebLogic Server creates multiple EJB instances as necessary to process large volumes of messages concurrently. This stands in contrast to a standard JMS messaging system, where the developer must create a MessageListener class that utilizes a server-wide session pool. Thus choice A is incorrect. Thus choice B is correct. Whereas a JMS MessageListener is tied to specific session pools, Queues, or Topics, message-driven beans can be developed independently of available server resources.
Thus Choice C is also correct. If your application requires a single JMS consumer to service messages from multiple Queues or Topics, you must use a standard JMS consumer, or deploy multiple message-driven bean classes.
Thus Choice D is incorrect. To allow a debugger to attach to the virtual machine that WebLogic runs you have to start WebLogic in debug mode. In order to start WebLogic in debug mode using a Sun virtual machine follow these steps start with step one only if using a Solaris platform : 1.
Add the following parameters to the java command line before the "weblogic. Server" string that launches WebLogic server: -Xdebug.
BEA WebLogic Server Interview Questions & Answers
How do we determine the version of the WebLogic server? These are the files that we have to use based on the OS type Windows or Linux : 1. What are the different ways used to deploy your applications in a WebLogic server? How do you turn off the auto-deployment feature in WebLogic server? Ans: Auto deployment mode feature of WebLogic server works for the development mode, where it checks every 3 seconds to see if there are any new applications available or any new changes available for the existing applications and deploys them. To disable the automatic deployment, these are the available options: 1. Selecting Production mode checkbox from the Administration Console for the necessary domain.
WebLogic Interview Questions And Answers
The enhancements support for WebLogic Server messages is provided by T3. T3 is superset of java Object. Serialization and RMI can be done over T3. What happens when a failure occurs and the stub cannot connect to a WebLogic Server instance? The stub removes the instance that is failed from its list, when a failure occurs. The stub uses DNS again for finding a running server and obtains a current list of instances, when there are no servers left in its list. The list of available server instances in the cluster will get periodical refreshment, which allows making the advantage of new servers.