Following are the questions answered to one of the mailing lists. Here it is shared..... Usually Performance issues with JVM's are related either to, 1. JDK Bugs 2. JVM thread deadlocks and memory leaks 3. Application request taking too long to process ex. long running query, poor sql, db issues or java coding 4. Poor performing Garbage collection 5. Incorrect JVM startup settings The amount of memory that should be allocated to each JVM depends on the number of JVM's, the number of users on the system, the amount of physical memory on the middle tiers, the habits of the users and the version of the JDK used by the system. THe version of JDK being used makes a large difference to how the memory and the number of JVM's should be sized. JDK 1.3 performs better with more JVM's and less heap while JDK 1.4/1.5 performs better when there are less JVM's and more heap. Thumb rule is to have 1JVM per 2 cpu's with increased heap parameter for better performance. As a mini...
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