tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Caldarale, Charles R" <Chuck.Caldar...@unisys.com>
Subject RE: Tomcat Thread utilization growing very large causing a hung tomcat instance
Date Tue, 03 Aug 2010 15:19:04 GMT
> From: Tomcat Novice [mailto:tomcat.novice@gmail.com]
> Subject: Tomcat Thread utilization growing very large causing a hung
> tomcat instance
> 
> I have been encountering issues where a particular tomcat 
> instance/s are having large thread count during load testing
> and results in a hung state.

I suspect that your code is spawning threads, and not managing them properly.  Your horribly
formatted stack trace shows timer threads being started by:

at com.hp.ov.sm.client.common.communications.HeartBeat.(HeartBeat.java:68) 
at com.hp.ov.sm.client.common.communications.SOAPClient.connect(SOAPClient.java:237) 
at com.hp.ov.sm.client.webtier.WebClient.connect(WebClient.java:95) 
at com.hp.ov.sm.client.webtier.WebController.init(WebController.java:599) 
at com.hp.ov.sm.client.webtier.WebControllerServlet.index(WebControllerServlet.java:448) 
at com.hp.ov.sm.client.webtier.WebControllerServlet.process(WebControllerServlet.java:366)

at com.hp.ov.sm.client.webtier.WebControllerServlet.processHTTPRequest(WebControllerServlet.java:317)

at com.hp.ov.sm.client.webtier.WebControllerServlet.doGet(WebControllerServlet.java:255)

(The next time, leave the line breaks in the trace, please.)

> 1. Any ideas how I can resolve/isolate this problem?

Fix your webapp to manage threads properly.

> 2. I know I need to do a thread dump but I am not familiar on how to
> analyze thread dumps from Tomcat. Can you point me to documententation
> on how I can analyze thread dumps from Tomcat?

Take a thread dump on a Tomcat that's been used but now idle, and then one on the problematic
system, and compare.

> 3. Also, can someone confirm if the thread dumps from JDK 1.5 are the
> same as the Thread Dumps from a JDK 1.6? I seem to be getting different
> formats. Can someone just confirm?

I don't recall any major differences, but they are unlikely to be identical, since minor enhancements
to the JVM are made all the time.

> 4. If the maxThread is set to 200, why are the Tomcat instances
> utilizing up to 400 Threads (see screenshot)

There isn't a screenshot (the mailing list strips most attachments).  Post data, not pictures.
 Also post your server.xml so we can see what you have configured, but please remove the commented-out
bits (and passwords) before doing so.

 - Chuck


THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus
for use only by the intended recipient. If you received this in error, please contact the
sender and delete the e-mail and its attachments from all computers.


---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
For additional commands, e-mail: users-help@tomcat.apache.org


Mime
View raw message