Rob Woollen

Every developer has experienced it. The application that ran so well in testing hangs or performs miserably under load. While there are many possible causes of performance degradation or hangs, this article can't possibly cover them all. Instead, we'll look at three common mistakes in WebLogic Server applications that can deadlock the server or bring your performance to a screeching halt. Thread Dumps The best Java tool for diagnosing deadlocks is a Java virtual machine thread dump. A thread dump is a snapshot of the virtual machine's current state, including stack traces for each Java thread. Many virtual machines also include information about the Java monitors held by each thread. Monitor information is especially useful for diagnosing deadlocks and performance problems in your application. On Windows platforms, you can generate a thread dump by pressing Ctrl-Bre... (more)

Best Practices For Writing EJB Applications

JavaSoft defined the Enterprise JavaBeans specification to give Java developers a foundation for building distributed business components. EJBs are Java components that implement business logic and follow a contract designated in the EJB specification. Enterprise JavaBeans live inside an EJB container that provides a set of standard services, including transactions, persistence, security, and concurrency. This means that the application programmer is freed from developing these services from scratch. To get the most out of using EJBs in an enterprise-level distributed applicatio... (more)

Avoiding Performance Pitfalls with Entity EJBs

Entity Enterprise JavaBeans (EJBs) are a convenient means to map persistent data to Java components. Container-Managed persistence (CMP) provides rapid development since the EJB container automatically handles loading and storing the persistent data. However, along with their many advantages, Entity EJBs can lead to very slow performance when used incorrectly. This column details a few common pitfalls which trip up EJB programmers and hinder the performance of their Entity beans. Primary Key Classes Like a database row, entity beans have an associated primary key. This primary k... (more)