Web Hosting Talk : Web Hosting Main Forums : Hosting Security and Technology : Tomcat increases load in server

[digitaldreams]

we have a system with redhat enterprise linux 3.0 running a web
app with tomcat 4.1, apache 2.0.49 and mysql 4.1. once in a while
the load average in the server increases to 20.00 , the load
decreases only when we stop or restart the tomcat . what could
be the reason and how to solve this issue.
pls help me.
senthil

[fastdeploy]

Originally posted by digitaldreams
we have a system with redhat enterprise linux 3.0 running a web
app with tomcat 4.1, apache 2.0.49 and mysql 4.1. once in a while
the load average in the server increases to 20.00 , the load
decreases only when we stop or restart the tomcat . what could
be the reason and how to solve this issue.
pls help me.
senthil

I used to work a lot on Tomcat servers--major mission-critical transaction-oriented financial application--not as a developer, but as a sysadmin. You will probably want to use a memory profiler to determine what is eating up system resources. See:

http://jakarta.apache.org/tomcat/faq/memory.html

...for information on memory profiling.

Many versions of Tomcat are buggy and have memory leaks. 4.1 is QUITE old also (2 years?). You might consider upgrading to the 5.5.x series, though test it carefully first as you might get incompatibilities or conflicts with new jars.

As an aside, this is not a problem you should be concerned with if you are the sysadmin. Developers should be aware of and know how to use debugging tools.

[sprintserve]

For JSP/Servlets, the issue is usually the lack of RAM. These boys are memory guzzlers. Due to the lack of information, I can only guess that what's happening is that a certain script uses more RAM than you have, and is moving into SWAP. That usually causes a nasty spike in loads.

Check your memory usage / SWAP when you next have a spike in load.