[alberto.silveirajunior]

From what i see the maxInstances by default is 20 so i don't know how 854 instances were created in first place. Are any configurations changed on your setup?

All configurations (jboss and tomcat) are the default.

When you said maxInstances, are you talking about that tomcat configuration (server.xml) maxThreads which the default is 250? Or are you talking about some other configuration?

Here is the configuration that I have:

<!-- A HTTP/1.1 Connector on port 8080 -->


Btw...could you solve your problem?

Also, thanks for your reply/help!

[alberto.silveirajunior]

Actually...here the configuration that I have:

Connector port="8080" address="${jboss.bind.address}"
maxThreads="250" strategy="ms" maxHttpHeaderSize="8192"
emptySessionPath="true"
enableLookups="false" redirectPort="8443" acceptCount="100"
connectionTimeout="20000" disableUploadTimeout="true"

thanks...

[jaikiran]

When you said maxInstances , are you talking about that tomcat configuration (server.xml) maxThreads which the default is 250?

No, maxInstances and maxThreads are 2 different things. From what i read in some mailing lists, the maxInstances is not (easily) configurable i guess. But that still leaves the question, how did it end up creating 854 instances.

[alberto.silveirajunior]

I understand. Yesterday I took some time to read about.

Here they explained how to set a new value to this "maxInstances" attribute:

http://mail-archives.apache.org/mod_mbox/tomcat-users/200803.mbox/[e-mail]%3E

Do you know if there is some monitor, tool, jboss web-console, etc... where I can check the real time "maxInstances" value?! Otherwise how can I know that I need to increase this "maxInstances" value?

But as you correctly said..."how did it end up creating 854 instances"...

I have no idea.

[jaikiran]

I think the right place to start debugging is your application's servlets to see how the requests are being handled:

"jaikiran" wrote:

By the way, a quick google search tells me the reason why the instances are not unloaded :

Usually servlets that haven't finished servicing requests.

[alberto.silveirajunior]

I think the right place to start debugging is your application's servlets to see how the requests are being handled

Its a very peculiar application. The most important piece of this application uses an AJAX function to send HTTP requests to the JBOSS/Tomcat every 0.9 seconds. We should have around of 100 users logged 8 hours per day sending requests every .9 secs.

I believe that something is building up, and after some load (3 days) it just stop to respond HTTP requests.

So far its only a theory... I couldn't find a final solution.

My partial solution is restart the JBOSS every night.

Thank you once again.

[alberto.silveirajunior]

Just to give you all a feedback.....

Finally I found why JBOSS stops to respond HTTP requests.

I found an error in my application where the application code was leaving DB connections starving.

When the maximum number of busy connections is equals to the max number of connections, JBOSS/tomcat stops to respond HTTP requests.

This application uses hibernate 3x and C3PO.

I hope it can help you some day...

Thanks,

[jaikiran]

Thanks for posting this - it will atleast give someone an idea to where/what to look for while debugging similar issues.

[georzal]

Hello to all.

We have a similar problem. Not understand why every day hangs the server.

I do not understand what it means "Waiting for X instance(s) to be deallocated"??

It's good or bad. What is it and what is the normal number of that instances. How to set the maximum and minimum if it is possible??

INFO: Server startup in 40322 ms
Aug 30, 2010 10:30:33 AM org.apache.coyote.http11.Http11Protocol pause
INFO: Pausing Coyote HTTP/1.1 on http-18080
Aug 30, 2010 10:30:34 AM org.apache.catalina.core.StandardService stop
INFO: Stopping service Catalina
Aug 30, 2010 10:30:35 AM org.apache.catalina.core.StandardWrapper unload
INFO: Waiting for 184 instance(s) to be deallocated
Aug 30, 2010 10:30:36 AM org.apache.catalina.core.StandardWrapper unload
INFO: Waiting for 182 instance(s) to be deallocated
Aug 30, 2010 10:30:37 AM org.apache.catalina.core.StandardWrapper unload
INFO: Waiting for 178 instance(s) to be deallocated
Aug 30, 2010 10:31:44 AM org.apache.catalina.startup.Embedded initDirs

Thanks to all, a hope anyone knows the answers to these questions.

[ericxbenoit]

Hi,

I have the same exact problem with JBoss 4.2.1 (java 1.6.0 update 2).

It deploys the EAR and it can be accessed without any problem and suddenly (random) JBoss doesn`t respond anymore. We have to stop/start the service to "fix" the problem. After we stop and start the service it works fine until next time the problem happen...

If someone has a solution to this problem it will be really appreciated !

Thanks.

[viktor.meszaros]

Hi,

We had the same problem with our productive system.

Try to use jstack to print the thread dump. It is part of jdk 1.5 and higher. It can discover java deadlocks, which was our case.

jstack <java_pid>