too many http sessions with grails and memcached-session-store

I am a litle bit lost here.

I am using a grails application deployed in tomcat with memcached-session-store. That it uses spymemcached.

I am also using melody plugin to monitor the app.

In the righter-upper part, there is a http-sessions graph that only grows.

We need to know if this is a potential problem. For now, and without know, we daily restart the webservers. And as a last test we are going to let the http-sessions grows to see if in the future it tends to clean it self.

This is the graph that I am talking about:

So: is a problem? Do I have to configure memcached, tomcat, grails, memcached-session-store or spymemcached to expirate the sessions with a less expiration time? I couldn't find in Interet how to do that.

Any pointer would help.

thanks in advance

AFAICS there were 117 concurrent sessions at max, which are not too many generally. You can also limit the maximum number of active sessions in your context.xml/server.xml via maxActiveSessions for the manager btw.

Some questions:

• Do you experience any issues (e.g. running out of memory or anything else)?
• How much memory is available to your jvm?
• How much memory is used by the jvm?
• Do you know how many sessions your app can handle?
• What's your session expiration?
• What's the size of your (serialized) sessions? You can e.g. check jmx stats from memcached-session-manager (see JMXStatistics).

Finally I'd say that you should keep your tomcats up and running until you experience any real problem.