Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Henri Gomez
Something we should also check is the CPU load of the Tomcat instance. May be it will be usefull also to let users/admin add their own counters in the load estimation. For example, if some admins considers we should base the load-balancing on HTTP requests or SQL access, and they have these

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread jean-frederic clere
Henri Gomez wrote: Something we should also check is the CPU load of the Tomcat instance. May be it will be usefull also to let users/admin add their own counters in the load estimation. If you want to add this to Tomcat remeber that stuff needs a JNI module to collect information from the

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Henri Gomez
Well many beans are allready available : java.lang.Theading java.lang.MemoryPool I could see also some beans related to CPU load but using a Sun JVM (not on IBM). 2007/7/5, jean-frederic clere [EMAIL PROTECTED]: Henri Gomez wrote: Something we should also check is the CPU load of the Tomcat

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Yefym Dmukh
Hi Rainer, seems we have still an issue in jvm config. we have not noticed the concurrent mode gc failures that led to tomcat overload and bad responses. 14896.148: [Full GC 14896.148: [CMS (concurrent mode failure): 1102956K-326641K(2359296K), 4.0684463 secs] 1280549K-326641K(3067136K), [CMS

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Yefym Dmukh
Hi Rainer, seems we have still an issue in jvm config. we have not noticed the concurrent mode gc failures that led to tomcat overload and bad responses. 14896.148: [Full GC 14896.148: [CMS (concurrent mode failure): 1102956K-326641K(2359296K), 4.0684463 secs] 1280549K-326641K(3067136K), [CMS

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Mladen Turk
Yefym Dmukh wrote: Actually the following was happening: the LB sends requests and gets the session sticky, continuously sending the upcoming requests to the same cluster node. At the certain period of time the JVM started the major garbage collection (full gc) and spent, mentioned above, 20

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Mladen Turk
Yefym Dmukh wrote: Actually the following was happening: the LB sends requests and gets the session sticky, continuously sending the upcoming requests to the same cluster node. At the certain period of time the JVM started the major garbage collection (full gc) and spent, mentioned above, 20

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Mladen Turk
Yefym Dmukh wrote: You have oxymoron here. With session stickiness you are willingly tear down the load balancer correctness because you don't wish/can have session replication. Generally you are right, but the ideal world is not the reality: we use apache my faces implementation of jsf where

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Yefym Dmukh
it simple approach ? Mladen Turk [EMAIL PROTECTED] 05.07.2007 13:19 Please respond to Tomcat Developers List dev@tomcat.apache.org To Tomcat Developers List dev@tomcat.apache.org cc Subject Re: Feature request /Discussion: JK loadbalancer improvements for high load Yefym Dmukh wrote

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Yefym Dmukh
Mladen wrote: This won't help much. The sticky session requests must be served by the same node (group of nodes if using domain clustering), and your requests will still be delayed by the JVM instance GC cycle (It has to happen sometime, and you cannot depend on request void intervals) The main

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Rainer Jung
OK, this culd make sense, i.e. heap nearly full on node1 failover to other cluster member node2 (replcation assumed) and trigger GC by System.gc() on node1. Interesting idea ... (for JK3 and beyond). Yefym Dmukh wrote: Mladen wrote: This won't help much. The sticky session requests must be

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Filip Hanik - Dev Lists
Question, why would you need GC,heap or CPU stats from the Tomcat machine at all? in most cases, none of these stats can predict response times. The best way would be to simply record a history of response times, and then mod_jk can have algorithms (maybe even pluggable) on how to use those

Re: Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-05 Thread Yefym Dmukh
Question, why would you need GC,heap or CPU stats from the Tomcat machine at all? in most cases, none of these stats can predict response times. The best way would be to simply record a history of response times, and then mod_jk can have algorithms (maybe even pluggable) on how to use those

Feature request /Discussion: JK loadbalancer improvements for high load

2007-07-04 Thread Yefym Dmukh
Hi all, sorry for the stress but it seems that it is a time to come back to the discussion related to the load balancing for JVM (Tomcat). Prehistory: Recently we made benchmark and smoke tests of our product at the sun high tech centre in Langen (Germany). As the webserver apache2.2.4 has