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From Yefym Dmukh <>
Subject Re: Feature request /Discussion: JK loadbalancer improvements for high load
Date Thu, 05 Jul 2007 15:25:41 GMT
>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 stats for future request.

As for me the Busyness algorithm in mod_jk is almost perfect as well as 
idea as implementation , 
the only weak point is that it balances the jvms on the background.  The 
point is that Jvm has such an artifact as GC which under the circumstances 
makes deny of service for awhile :) and loadbalancer notices is too late, 
even worse because of any reasons (stickness or internal logic with jobs 
queue) the lb doesn^t react accordingly at the right time.

All other issues like threading and cpu are not from me. To my opinion 
they are useless. I was talking only about JVM loadbalancing which reacts 
accordingly on JVM specific things.

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