InfoCenter Home > 4.5: Dynamic fragment cacheA WebSphere Application Server performance enhancement is the ability to cache the output of dynamic servlets and JSP files, a technology that improves application performance. This technology, working within an application server's Java Virtual Machine (JVM), intercepts calls to a servlet's service method, and checks whether the invocation can be served from a cache. Because J2EE applications have such high read-write ratios and can tolerate a small degree of latency in the freshness of their data, fragment caching creates an opportunity for significant gains in server response time, throughput, and scalability. After a servlet is invoked once (generating the output that will be cached), a cache entry is created containing not only the output, but also side effects of the invocation as, for example, calls to other servlets or JSP files, as well as meta data about the entry including timeout and entry priority information. Unique entries are distinguished by an id string generated from the HttpServletRequest object for each invocation of the servlet. Servlet caching can then be based on:
Summary of dynamic fragment caching articlesThe dynamic fragment caching documentation describes how to configure dynamic caching in WebSphere Application Server. For both global configuration and the definition of individual cache policies, users can configure dynamic fragment caching through XML files installed on the server, or with graphical user interface (GUI) tools such as the administrative console or the Application Assembly Tool. The XML files are the preferred method for configuring dynamic caching because, in some cases, they are easier to implement and include more function than the GUI configuration. The dynamic fragment caching articles also discuss advanced features of the cache, such as how to control external caches and how to build user-defined drop in components to customize the cache operation. The dynamic fragment caching articles are:
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|