Openfire load problem

I have started using openfire of late and has seen a general trend in it.

Once the load on the server begins to rise, it just keeps on increasing and never comes down till a restart is done.
After the restart, it works fine for 12-15 hours.

Can you suggest me on how to look into this?

Which version are you using? Which Java vendor and version?

Openfire - 4.2.3
Java - 8