agent cannot connect to the server. java.lang.ClassNotFoundException: org.hibernate.collection.PersistentMap

John Mazzitelli mazz at
Fri Jun 25 17:34:29 UTC 2010

> This box has just one JBoss and standard linux services. I didnt change
> default measurement intervals. So OOME cannot be due to excessive number
> of metrics being collected, can it?.

That's a very minimal setup. The number of metrics won't be involved here.

> Im pretty sure it relates somehow to my changes of the RHQ server address. If agent cannot connect to the
> server - does it keep metrics in memory to send them to the server
> later? Or maybe failed connection retry leaks some resource? (socket,
> memory or file handler)

If the server goes down, the agent will spool messages to disk and when 
the server comes back, those messages will be loaded into memory and 
sent to the server. The spool is upper-bound-limited through the 
configuration (I think its something like 100MB - any new messages to 
get spooled will push out the oldest messages).

We've seen instances in the past where failed connection retries causes 
leaks, but that was a while ago and I think we fixed those in previous 
releases. Search the bugzilla issues if you want to see if you can find 
something similar.

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