2010/10/26 Mladen Turk <mt...@apache.org> > On 10/26/2010 02:47 PM, Marc Wilmots wrote: > >> Hi Experts, >> >> I have the following setup: >> >> Apache1 >> / \ >> Apache2 Apache3 >> \ / >> Tomcat1 >> >> All Apaches are version 2.2.3 (RedHat) >> Apache2 and Apache3 loadbalance Tomcat1 (6.0.18) with mod_jk (2.2.28). >> >> In idle state the AJP connector of Tomcat1 only has 7 active connections. >> After launching a stress test of Tomcat1, it's AJP connector has reached >> maxThreads (200). After the stress test has finished, there are still 200 >> active connections in the AJP connector. >> >> Because of this, apache2 and apache2 cannot receive any heartbeat message >> anymore from the AJP connector and mark Tomcat1 as dead. I can access >> perfectly through port 8080, so Tomcat1 isn't dead at all! >> >> > You have a usual setup problem where the number of connections > in httpd fronting tomcat is too high for a tomcat. > And you don't have any mechanism for limiting those connections. > > Sorry, I realize I had to mention I have a total of 4 Tomcats, which in total make up a maxThreads of 800 (200 each). The Apaches have a maxClients of each 600 (1200 total).
1200 > 1000, thus your theory is probably right. However, I'm just wondering... I read that when Tomcat reaches the max number of connections, just rejects new connections (I'm omitting the backlog on purpose). So, I can understand that my Tomcat is reaching the maxThreads, but I'm supposing that once I stop my stress test, the connections should go down, and not remain there as "idle" as they do now. No load, means no more connections, so why does mod_jk keep the 200 connections occupied? I don't have anything set such as keepalive or whatever.. Shouldn't it just release the connections? Now, RHEL5 offers both the the prefork (default) and worker > (httpd.worker) mpm, so if you wish to use that topology of yours > you will have to do do two things. > 1. Use worker mpm > 2. Limit the number of connections from httpd to tomcat by > using connection pool (hint. maxThreads in Tomcat <= ServerLimit * > ThreadsPerChild) > > There is a nice calculator that my co-worker wrote: > http://lbconfig.appspot.com/ > > It's a simple and it'll generate all configs for you. > Wow! Indeed, it's very very nice. I love it! Thanks a lot! > > > > Regards > -- > ^TM > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > >
