Openfire Hazelcast Problem

I have used hazelcast plugin on 2 openfire instances and brought them in a cluster.
Now what is happening is my number of users connecting to it decreases.

One issue I see over here is the increase in the network bandwith which almost goes up by 10x.

I have 10x concurrent sessions at the same time.

Can you share some insights on it.??

What I am thinking over here is the objects which are transferred over the network from one instance to another.
I have started looking into the source code of openfire, but would be really grateful if you reply to this thread and share your insights.