After upgrading from Tomcat 5 to Tomcat 6 I encountered a situation where Tomcat cycles through working hard for 20 minutes, and slowing down for 10 minutes.
We run a Java servlet application using JDK 1.5.0-15 and Tomcat 5.5.26. One part of the application processes an XML file, and this can saturate the blade running Tomcat. To overcome this we tested in a environment using Apache (httpd 2.2.3-11) to load balance Tomcats on separate blades using mod_proxy_ajp. This worked well. I upgraded the JDK to 1.6.0-07. I saw an increase in throughput of around three requests per second when using mod_proxy_ajp to a single Tomcat. This was without recompiling the Java code. I then upgraded to Tomcat 6.0.18. Throughput took a slight hit of one request per second. I was testing using WebLOAD running one test over five minutes on each configuration and another over one hour. An anomaly showed up in the one hour Tomcat 6 testing. Twenty minutes into the test throughput dropped from around 40 requests per second to two requests per second for a period of around 10 minutes. This occurred later in the test as well. At the time of the slow down the utilisation of the Tomcat blade dropped from 70% to 30% (as reported by top). The behaviour is similar if I go directly to Tomcat using port 8080. This behaviour is repeatable on Tomcat 6, but does not occur on Tomcat 5. The application is not logging any errors. Monitoring using jconsole does not show anything out of the ordinary. Has anyone seen this sort of behaviour when upgrading to Tomcat 6? If not, does anyone have any idea of how I may be able to determine the cause of this behaviour? Thanks, Bryan --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
