Lists wrote:
> Hi,
>
> We have a Tomcat app that is loadbalanced by hardware. I have 4 boxes
> available in our test env, all of which vary slightly but not massively in
> spec.
>
> Anyway I moved from 2 tomcat instances on each machine ( listening on
> different ports ) down to 1 and I noticed for the same load the cpu
> utilisation dropped by 20%. Interesting, how can this be explained? Is
>
My guess (and that's all it is) is that you have eliminated much of the
context-switching overhead that two instances would have compared to one.
> this the extra effort in tomcat or something? Or is it memory related? the
> 2 instances had 1gb each, and the single one has been given 4gb. However I
> have jprofiled the instance and it has never seemed memory hungry. Anyway I
> suspect even at 2gb for 1 instance it would still be 20% less cpu - i can
> always do a run to prove this if people think that necessary..
>
> Another thing i've found is that on one server I have abnormally high CPU
> utilisation for the same load. I've checked the logging levels are all the
> same as are the java VM and the VM config settings. I wonder what else
> could cause this? All i can think is some sort of OS or hardware
> malfunction! maybe the CPU cache is duff or something.
>
What is this cpu (type and speed) compared to the others? If it's a
slower or less-capable (no numeric coprocessor, etc) cpu, the same load
would be a high percentage of its capability.
> Many thanks to any input to my Friday weird-ness!
> Dan
>
---------------------------------------------------------------------
To start a new topic, e-mail:
users@...
To unsubscribe, e-mail:
users-unsubscribe@...
For additional commands, e-mail:
users-help@...
