I have Tomcat 6.0.16 running on a box, and Apache 2.2.11 running on another box, both running on windows server 2003 and am using Mod_JK 1.2.23 for communications between the two.
I have had a recurring problem where after a few days, usually 3 or 4, the AJP listener on the tomcat seems to stop working correctly. The apache starts displaying 503 service temporarily unavailable messages, and when I check the mod_jk.log file it says it can't connect to the tomcat. All it takes is restarting the tomcat and everything starts working again. Here is what troubleshooting I've done so far: I checked the tomcat via its http port 8080, and the application comes up fine. I check the tomcat box and make sure the AJP listener is still up and listening using netstat and it shows as listening. When I telnet to it (either locally or from the Apache box), it accepts the connection.. holds it open for a few seconds.. maybe 15.. then closes it. However when I telnet to the AJP listener port on the tomcat box when everything is working, it accepts the connection and it pretty much stays open until I use control C to close it. I realize this isn't exact troubleshooting, but it's just something I've noticed when looking into this. So to me it looks like only the AJP listener is having issues. When I pull the Application up via 8080 it works fine, I can use it and do everything like I could when the connection between apache and tomcat is working. I've tried decreasing the time before an idle session expires, increased the memory usage limit on the tomcat from 64 to 256mb (it defiantly was not big enough), and even tried restarting the tomcat before this happens to prevent it from happening(which made no difference on the 3-4 day timetable). Any ideas, questions or suggestions are welcome. Thanks Rusty SA