Map (HashMap) Instance Member Performance Issue in @Service ,@Local EJB

[rodedh]

Hi,

I encountered a performance issue when using the a HashMap instance contained in an EJB. I will call it A

I used the following annotations in order to use an EJB as a singleton: @Service, @Local

In the EJB I have a member: an instance of HashMap<String, Object>.

I noticed that when I access the HashMap (via get method) from other EJB B (A is injected in B) the time in most cases is somewhere near 0 ms BUT every few iterations the time is 16ms(!).

As number of these (map.get invocations) 16ms might reach 4000 this makes performance very poor.

Now,

When made EJB A(the singleton) a non EJB but just a simple POJO this behavior reduced almost to zero.

What can be the explenation? Where can I start trying to understand this behavior?

Thanks,

Rod

[peterj]

It could be garbage collection. Eventually, even with using a POJO, you would also see the occasional 16ms response. I suspect that with using the EJB more objects are being created, and thus the increase GC activity.

[rodedh]

Thanks. That what I suspected. Do you have an idea of how to control/monitor this issue? This is a real performance issue from my point of view.