Java Reference
In-Depth Information
The performance gains are substantial and the overhead
minimal, while the programming model is unaffected. The
merits of caching to improve performance are well
understood. Unfortunately, the current Java EE specification
does not include a mechanism for servlet/JSP caching.
However, WebSphere Application Server provides support
for page and fragment caching through its dynamic cache
function without requiring any application changes. The
cache policy is specified declaratively and configuration is
through XML deployment descriptors. Therefore, your
application is unaffected, remaining Java EE specification
compliant
and
portable,
while
benefiting
from
the
performance
optimizations
provided
from
WebSphere's
servlet and JSP caching.
The performance gains from dynamic caching of servlets and
JSPs can be substantial, depending on the application
characteristics. Performance benefits go up to a multiplier of
10 from applying dynamic caching to an existing RDF
(Resource Description Format) site summary (RSS) servlet.
For additional performance gains, the WebSphere Application
Server servlet/JSP results cache is integrated with the
WebSphere plug-in ESI Fragment processor, the IBM HTTP
Server Fast Response Cache Accelerator (FRCA) and Edge
Server caching capabilities. For heavy read-based workloads,
significant additional benefits are gained through leveraging
these capabilities.
For another example of the principle take advantage of the
WebSphere Prepared Statement Cache when writing JDBC
code. By default, whenever you use a JDBC
PreparedStatement in WebSphere Application Server, it will
