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From Marc Wilmots <>
Subject Re: mod_jk makes ajp connector run out of free connections
Date Fri, 05 Nov 2010 00:01:35 GMT, I didn't.
The mod_jk scared the hell out of me....wouldn't you? :-)

"Using this option will have a strong performance penalty for Apache and
Tomcat. Use this only as a last resort in case of unfixable network

I'll give it a try tomorrow and see what it gives.

By the way, my last calculation about connection_pool_size was wrong. I
forgot to include the second Apache server. The math would look like this

Apache1 -> 10 server processes x 15 x 4 (tomcats) = 600
Apache2 -> 10 server processes x 15 x 4 (tomcats) = 600, which makes 1200 in

Each Tomcat would receive a maximum of 300 connections, which would leave
100 free connections per Tomcat. This would solve the problem that Tomcat
runs out of connections. The thing is...not all of my available Apache
connections can be used:

Apache has 60 threads per server process (10) -> 600 connections.
connection_pool_size per server process: 15. This would mean only 15 of 60
possible connections per server process can actually establish a connection
to Tomcat.

In order to be able to server all Apache connections simultaneously, I would
need 4 more Tomcats?

2010/11/5 Mark Thomas <>

> On 04/11/2010 19:27, Marc Wilmots wrote:
> > The best solution would be to enable DisableReuse as Mark stated,
> although
> > I'm afraid that would be too big of a performance hit.
> Have you tried it?
> The cost of the required CPING/CPONG isn't that different to the cost of
> creating a TCP/IP connection. On a fast local area network I doubt you'd
> notice it. The time taken to establish a TCP/IP connection is usually
> (YMMV so test it) << the time taken to process a request.
> Mark
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