Jboss 4.x :Sudden GC growth leading to jvm crash

[samwily1972]

I have seen a lot of memory leaks but this is different . I have 4 JBOSS instance per host and have a few servers. Suddenly I see a few jvms shoot up the GC heap from 500meg to 2.gig limit and throw java.lang.OutOfMemory exception . After further analysis and troubleshooting only thing that we could connect this to was a database issue as we saw quite a few of these exceptions in the faulty jvms. We also noticed ORA-3136 error in DB machines

WARN [org.jboss.resource.connectionmanager.JBossManagedConnectionPool] Unable to fill pool
org.jboss.resource.JBossResourceException: Could not create connection; - nested throwable: (java.sql.SQLException: Io exception: Con
nection reset)

Question is why does the JVM/JBOSS leak/grow/use memory when it cant maintain the minimum connections to database specified in the datasource ? Are there any known issues as this ?Could it be a JVM bug?

[peterj]

Set the JVM option -XX:+HeapDumpOnOutOfMemoryError. This will generate a heap dump file the next timne this error happens. Load that file into VisualVM (or any other tool that will analyze the heap dump); that should give you some idea about what is eating up the memory.