WebSphere Application Server V7.0: Concepts ... - IBM Redbooks

► Improved 64-bit performance
When using the 64-bit version of Java SE V6 the usage of compressed
references provides significant improvements in memory footprint and
performance. By using this technique, heap sizes up to 25 GB are possible
while the overhead of a pure 64-bit implementation is reduced.
► Higher garbage collection (GC) throughput
Although the core GC technologies are the same as in version 5 of the SDK, a
new implementation of the GC component provides an improved footprint and
faster class loader performance. Additional performance improvements like
hierarchical scanning were implemented for the gencon policy.
7.1.3 DMZ secure proxy
The DMZ secure proxy server can be placed in the architecture to replace a Web
server with a plug-in. Performance tests have shown that a performance benefit
of up to 15% can be achieved using the DMZ secure proxy, compared to the Web
server plus plug-in configuration.
Additionally it can be expected that the DMZ secure proxy scales better than the
traditional Web server plus plug-in configuration. Thus you might end up with
fewer servers. You should perform proper testing in your environment to figure
out what configuration performs better in your specific environment.
7.1.4 Flexible management
7.2 Scalability
Under the aspect of flexible management, two types of servers: administrative
agent and job manager, were introduced in WebSphere Application Server V7.0.
The main purpose of these server types is to increase administrative scalability.
For more information about flexible management refer to 3.2.4, “Flexible
management” on page 78.
Scalability, in general terms, means adding hardware and software resources to
improve performance. However, adding more hardware might not necessarily
improve the performance of your environment if your systems are not tuned
properly or it your application is not scalable. Before investing in additional
resources, you should understand the workload characteristics of your systems
and ensure that your systems are properly tuned for this workload.
Chapter 7. Performance, scalability, and high availability 231