Re: unexpected high cpu load
On Mar 22, 2010, at 2:56 PM, Marco Laponder wrote: Hi, I am experiencing,while running my web application, a very high load on the system where Geronimo is running (4 cpu's are busy). I tried to find the cause of the problem by sending a kill -3 and inspecting the java vm thread dump. I attached it to this mail but I couldn't detect the cause of the problem of the CPU usage. A number of threads are in the containsKey on the hashmap triggered by the getResource on the MultiParentClassLoader which strikes me as odd, can this be the source of the problem ? Are there other ways to determine why the CPU is load is this heavy? Any tips are appreciated. One simple test is to create several thread dumps and compare the two. Java profiling tools, java debugger, logging, etc. (in no particular order) are additional techniques... Looking at your thread dump, I see 4 threads in NavigatorTalkbackMgr.getMessage() doing a wait() (I assume they have a relatively long or infinite wait time) and 4 threads in MultiParentClassLoader.getResource(). The getResource calls definitely look suspicious... I'll bet a beverage of choice that there's been a concurrent read/write on the resourcesNotFound HashMap, the write thread caused the HashMap to be resized, and the read threads are now stuck in an infinite loop in HashMap.containsKey(). MultiParentClassLoader.getResource() is definitely wrong and needs to prevent concurrent access to the resourcesNotFound HashMap. Please create a Jira -- patches are also welcome! :) --kevan
EJB Life Cycle
I have been thinking about best practices with Geronimo. One of the things
that I have been thinking about is the life of EJB's inside the EJB container.
I am wondering if I should be setting used EJB's to null when I am done with
them or should I just let the container handle it. Example Code:
@Stateless
public class MyEJB implements IMyEJB
{
@EJB(name=AnotherEJBLocal)
private IAnotherEJBLocal m_anotherEJB;
// Do some stuff with m_anotherEJB;
protected void finalize()
{
m_anotherEJB = null; // Should I do this or let Geronimo handle it
}
}
Should I be including the finalizer code as I have it? Should I just let
Geronimo handle the life cycle? Is there a different/better way to handle
this? Any philosophical insight would be greatly appreciated. Thanks.
Russell Collins
Sr. Software Engineer
McLane Advanced Technology
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