My application hangs in Tomcat

[tin Gupta]

Hi All,

I have an application which is running in Tomcat 5.5. It is developed with the heavy use of Spring/Hibernate. It runs well for 1-2 hrs but then just hangs. Tomcat does not show any error (out of memory or some other) in the logs but does not respond to any request. I can only see the app's login page once it hangs.

In my application, a set of 10 jobs (Quartz API) get fired after every 5 minutes. I checked the logs and these jobs tohether take just 3 seconds to finish when the server is running normally. I have checked my code many a times but I doubt its my code's problem.

I have also tried increasing the heap size but it did not help either.

I am really confused as to what can be the issue. Is it some problem with Spring/Hibernate configuration, Memory leaks?

Please suggest me how can i really diagnose the problem and fix it.

Cheers,
Nitin

[Ben Souther]

One of the common causes of problems like this is running out of database connections. In your code are you always sure to close database connections after you use them?

[William Brogden]

You might try monitoring with Tomcat's Management application. You can see memory use and request Thread use. I was highly surprised one time to see that my Tomcat had maxed out request Threads due to an improperly removed application - result, it could not respond to new requests.

Bill