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
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