Tomcat Connector - high cpu usage

[Martin Thorpe]

Hello I have a problem with Tomcat running at 25% CPU useage. I have identified from the web that this is probably a problem with the ISAPI connector, but have found no information on how to fix this.

I am running Tomcat 5.5.20 on IIS 5, on Windows 2000 server.

I am using the binary connector for windows I have tried 2 versions 1.2.14.0 and the latest 1.2.19.0 but I still have the problem.
Below is my workers file, I wonder if there is anything in here that might help

worker.ajp13w.type=ajp13
worker.ajp13w.host=localhost
worker.ajp13w.port=8009
worker.connection_pool_size=10
worker.connection_pool_timeout=600
worker.socket_keepalive=1
worker.socket_timeout=60

Any hints or tips that I might bring this under control would be gratefully appreciated. By the way on my development version, of the same application, there is no problem but this is running through port number direct to Tomcat and not over IIS.

cheers
Martin

[Martin Thorpe]

Ok for anyone who might be interested it appears that I have fixed the problem, although I will have to monitor it over the next couple of days.

What I did in the end was to alter the connector in the Tomcat server.xml file:

so in tomcatRoot\conf\server.xml

I changed this line, which was the default Tomcat shipped with:

    <!-- Define an AJP 1.3 Connector on port 8009 -->
    <Connector port="8009" 
           enableLookups="false" redirectPort="8443" protocol="AJP/1.3"/>

To be this

    <!-- Define an AJP 1.3 Connector on port 8009 -->
    <Connector port="8009" 
           enableLookups="false" redirectPort="8443" protocol="AJP/1.3"
   maxThreads="50" minSpareThreads="5" maxSpareThreads="20"
           acceptCount="100" connectionTimeout="2000"/>

So specifying amount of threads and a connectionTimeout seems to sort it. Now it runs up to 16 - 25% when processing but drops straight back to 00 once finished as opposed to be constantly at 25%.

Hope it helps, I'll update if the problem re-occurs.

Thanks for reading
cheers
Martin

[Jeff Adama]

Martin,

THANK YOU !!! That was an increadibly HUGE help!!

I did not see this as identified in Apache's bugzilla and thus just submitted it as it presents show stopper for those needing to run Tomcat behind IIS and who are not lucky to find this page.
Here is the submitted bug report:
https://issues.apache.org/bugzilla/show_bug.cgi?id=47088

Jeff

[Rainer Jung]

Since there is a known bug in the tcnative Tomcat connector leading to 100% CPU load:

could you please check, if you have the native Tomcat connector running (aka
known as tcnative or APR connector)? It's running as part of Tomcat, not in the web server.

If so, which version of Tomcat and tcnative are you using, and can you please
try once, whether the problem also goes away by disabling tcnative?

Thanks

Rainer