>> how do you manage cross container caches if you are clustered - when >> you are using static members on classes? How do guarantee sameness on >> different physical machines? We do have a few caches in our >> application and are facing issues due to this design or an improperly >> implemented version of this design.
Also, be aware that caching can actually degrade application performance in some cases. Everything you cache takes space in the JVM heap, reducing what's left to process active requests. So it's possible to lose more cycles in GC than you saved by caching in the first place. You can just keep increasing -Xmx, but that can hurt you if the JVM starts using swap space/virtual memory for the Java heap.
If you're using a clustered cache, you also have the overhead of keeping the caches on each JVM in sync. That adds network as well as processing overhead for marshalling and unmarshalling cached objects.
In summary, J2EE webapp performance involves a lot of tradeoffs. Caching is important but has to be used judiciously to be beneficial.
-- Bill -- Bill Schneider Chief Architect
Vecna Technologies 5004 Lehigh Rd., Suite B College Park, MD 20740 [EMAIL PROTECTED] t: 301-864-7253 x1140 f: 301-699-3180
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