Arrakis run IBM Websphere 3.5.2 on Solaris using Sun JVM 1.2.2_07 for running web applications. The applications use heavy-weight serialized object as objectStreams between Java components. During concurrent user loads ( 30 users or more) the VM chokes and the performance sinks.

- The noticed bug is similiar to Bugs #4165204 and #4462602. But looks like the bug fix is not available for JDK 1.2.2.x.
From the thread dumps we see that the the last method we actually invoke is our copy method com.arrakisplanet.portfolio.item.BaseData.copy which call a bunch of
internal vm serialization methods....if we turn this copy off (which
means we may get mutated data downstream), the throughput and response
time numbers improve dramatically. so, once the copy is gone (done
via serialization) the same app runs just fine from a performance
perspective.

 The problem does not exist in 1.3.1. But cu cannot upgrade to 1.3.1. He wants the fix on 1.2.2.Cu tried on IBM jdk and hardware and the problem is not as bad. When they run on iax system, they can use 1.3.x since ibm webshere will work on it and the problem completely goes away.

The problem is seen on both of the following hardware and software.
SunOS lewis 5.8 Generic_108528-08 sun4u sparc SUNW,Sun-Fire
SunOS hermes 5.6 Generic_105181-23 sun4u sparc SUNW,Ultra-80