Should Tomcat 6 AJP keep its threads in keepalive state with mod_jk?

Question

I've recently switched my Tomcat server to use AJP fronted by Apache. In the manager I'm seeing:

Stage   Time    B Sent  B Recv  Client  VHost   Request
K   15395557 ms ?   ?   67.195.114.27   ?   ?
K   15859951 ms ?   ?   119.63.196.73   ?   ?
etc.

Is this a sign of the Tomcat holding the connection open far, far too long?

I'm aware I have some form of leak because periodically my app runs out of database connections and stops. I'm looking for evidence that the behaviour above is part of that problem. I'll note that the front end to this is a Javascript up communication using REST in Jquery.

Thanks a lot in advance.

Crossposted from ServerFault because I'm not seeing anything there. :-(

Answer 1

The AJP protocol is designed to work with long-running persistent connections. This is normal and expected. Both Apache and Tomcat will maintain connection/thread pools, and only create new ones when necessary.

This in itself isn't a compelling reason to suspect AJP for your memory leak, although if you started getting the leak after you moved to AJP, then clearly something is misconfigured somewhere.