MIght be an issue of the JVM version or the OS.
Do you see hs_err_pid#####.log file in the directories? That points to JVM crashes.
I would check the latest OS and JVM patches. Also you might use the same JVM as before (if there is an upgrade included), it might be that the newer JVM have such problems.
Also think about what you change during the upgrade ... any configuration, application patches or GC settings ...
I think I just figured out the issue here. We are using virtual servers from the same hosting company. For CentOS 5, the advertised 8GB of RAM boxes actually have 7.3GB. For the CentOS 6 boxes, the advertised 8GB RAM boxes actually have 6.9GB. We had our JVM option set to consume 7GB so I think it was trying to pull in RAM that wasn't there and dying. I have kicked it back to 6GB and figure that should fix the issue.
Thanks for the reply!