Openfire 3.6.4 out of memory

We installl openfire3.6.4 by rpm downloading from this site.

My java version is 1.5.0

The load testing tool is loadrunner8.1.Concurrent users is 2000.

I have modify the Xmx parameter to 1324m.

But the memory is 1.9G after 10 hours.We cannot login in the admin console.

I find the out of memory problem in the log files.

Another problem is the ACK.

Somebody think it’s the no Ack due to the problem,Is it?