system freezing for echo application in jboss (especially in the production).
Wed, 07/23/2008 - 05:57 — illi
Hi All
If I leave our product developed in echo(1.1) running in JBoss for a long time (hours), then eventually the system is freezing. This is happening in the production only. As a result, we have to restart jboss server once everyday. This is becoming real head-ache for me. Is it because of echo or any memory leaks in application or jboss memory settings.
What could be the problem? Is there any way to profile/loadtest the echo application to identify these memory leaks/ performance problems? how about echo 2.1?
Thanking you in advance.
First thing to determine is
First thing to determine is whether or not your objects are being garbage collected. Add some logging (System.err.println's are fine) to your finalize() methods of key objects, such as your Application instance and key major components of the application.
No version of Echo should do this, the likely scenario is that something is that a major portion of the application is not being garbage collected as its still being referenced elsewhere. All it takes is one static Map holding references to application objects to bring down a server.
I would recommend a good
I would recommend a good profiler. Although putting stuff in finalize() may work, it's a very tedious process. It requires modifying your code, and it even changes garbage collector behavior. I have used both JProfiler and Yourkit, they're both pretty good. You can download a trial version which is fully functional. They both provide ways of checking if GC is the cause. Yourkit provides an option to take a heapdump when available memory drops below a certain percentage of total heap, very useful to see which objects are leaking.
If you're using Linux you could also check out the jstat tool, that gives you all kinds of stats about the JVM, use jstat -help to see how it works. You could also take a heapdump manually using jmap and download one of the free tools that allow dump inspection. Haven't used one though so I can't recommend you one.
For an evaluation of Yourkit, see http://www.yourkit.com/download/.
Hth,
Niels
Thanks for the reply.
Thanks for the reply.
Recently we identified some issues like when trying to open a child dialog/ Window, the parent page is getting refreshed. Is it some normal refreshing or trying to reload the whole page (Is Ajax-enabled? )? Is there anything like client-side validations in echo1.1? What about the performance in echo1.1 compared to Spring Framework?
The issues you are referring
The issues you are referring to should not have anything to do with the system freezing. Freezing systems are usually memory-related (i.e. constant GC). Try to determine the exact cause first before you put too much work in stuff that's non-related.
Thank you very much for your suggestions.
Thank you very much for your suggestions.