Connection manager not holding connections under pub-sub load


We are using openfire for publish subscribe and we have a requirement to scale to more connections using connection manager.

Connection manager works well for pub-sub as long the number of publishes is low. When I have more publishes (in the order 10s per second) and have as low as 5 client connections, it drops the connections. The sessions are held fine when there is no load.

Any ideas on how to scale connection manager for pub-sub? I played with the parameters in manager.xml to increase connections to server and the threadpool but get the same behavior. Any suggestions will be helpful.