What is the load on your web servers? Could you repurpose a web server and load balance the app server instead? Most of the systems I set up replicate application servers and come to think of it I almost never get enough load on a single Apache HTTP server to need more than one box. (I'm speaking about load and NOT failover).
Sadly I don’t know anything about load balancing Tomcat and I'm usually doing BEA WL or WAS setups. I'm here to learn people... don’t flame me. Here is another couple .02 for you - hindsight is 20/20 but don’t you performance test before going 'live'? That is how we 'tune' our systems... run some serious load tests on your setup in a mirrored QA or staging environment prior to go-live. Then watch closely, use a code profiler or similar tools to see where the bottlenecks are. Play with the database and app server configurations... Sometimes turning up things like connections will actually seriously degrade performance for a myriad of other reasons. Apache JMeter running on several machines is a good load tester. If you have the $$ and the project is important enough... we have had great results from the Compuware suite of products, TrueTime etc. Good luck John Haro -----Original Message----- From: Kwok Peng Tuck [mailto:[EMAIL PROTECTED] Sent: Tuesday, July 29, 2003 12:47 AM To: Tomcat Users List Subject: Re: Production server tuning I'm no expert in load balancing and stuff like that, but shouldn't you load balance tomcat as well ? Antonio Fiol Bonnín wrote: > 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
