In theory, I'd go with Kwok's recommendation: one Apache with it's own load-balancer, and 3 Tomcats instead of 3 Apaches. However, in the real-world, this would require you to upgrade to Apache 2.0.x with the 'worker' MPM.
Yes, for your current config, you need to have your maxProcessors somewhere near 600 to handle peak load. For part two, go to each of your Apache machines and run: $ ps -ef | grep httpd | wc -l Add the numbers together, and subtract three (one for each of the Apache 'controller' processes). If the system has been running for awhile, this should be about the same as the number of connections to your Tomcat server on 8009, since mod_jk holds the connection open (by default) for the lifetime of the Apache child. The threads that are waiting for Apache to talk to them are blocked pending input, so aren't affecting Tomcat's performance in any way. Since you are using 4.1.9, I'm assuming that you are using the AjpConnector (instead of the newer CoyoteConnector). If you are using the WarpConnector, you are on your own ;-). With the AjpConnector, you can set the attribute 'connectionTimeout=xx-ms"' to have Tomcat drop the connection to Apache after xx milliseconds have gone by without traffic. For tuning, I like OptimizeIt (but it costs). I'm sure that other people will offer there opinions. "Antonio Fiol Bonnín" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Hello, > > We have already gone live, and we actually spend too much time dead. I > hope some of you can help me a bit about the problems we have. > > Architecture: > 3 Apache web servers (1.3.23) behind a replicated load balancer in DMZ > 1 Tomcat server (4.1.9) behind firewall, in "secure" zone. > 1 Firewall in between. > > Some facts I observed: > - Under high load, server sometimes hangs from the user's point of view > (connection not refused, but nothing comes out of them. > - Under low load, I "netstat" and I still see lots of "ESTABLISHED" > connections between the web servers and the Tomcat server. > > For the first case, I reckon I might have found the cause: > Apache MaxClients is set to 200, and Tomcat maxProcessors was set to > something about 150. Taking into account that there are 3 Apache, that > means 200 x 3 = 600 clients --> tomcat chokes. Just raised maxProcessors > to 601 ;-) > > For the second one, I have really no clue: > Apache MaxSpareServers is set to 10. I see more than 30 "ESTABLISHED" > connections even with extremely load. > > Could someone point me to either > - a solution (or part thereof, or hints, or ...) > - a good tomcat tuning resource > ? > > I hope I can find a solution for this soon... The Directors are starting > to think that buying WebLogic is the solution to our nightmares. They > think they only need to throw money at the problem. Please help me show > them they are wrong before they spend the money. > > Thank you very much. > > Antonio Fiol > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
