Optimization : Thread count

[Valery Anciaux]

Anyone familiar withe this option in the config.xml ?
<ExecuteQueue Name="default" ThreadCount="15" />
Is it accessible via the Weblogic console (6.1) ?
We are running on a Sun Solaris 420R (4 X UltraSPA
System clock frequency: 113 MHz) with 3072 Mb. What would be a suitable value for that parameter ?
Thanks,
Val�ry

[Mani Ram]

I don't think there is any thumb rule to set a value for this parameter. It is more application dependant.
Try changing the value and note the performance. Stick to the value when you feel the performance is good.
For more details, look here

[Chris Mathews]

This setting is very finicky and can have very adverse effects on your system. Set it too low and you create a bottleneck to your system. Set it too high and you are creating unnecessary overhead in your system, which may significantly decrease performance.
Experiment with your configuration and see what works best...
[ March 03, 2003: Message edited by: Chris Mathews ]

[Aaron Mulder]

Also, you need to balance the number of listen threads versus execute threads. If you have too many listen threads, the server may be actively handling 100 requests but only have enough execute threads to act on 15 of them, resulting in the other 85 sitting around waiting. If you have too many execute threads, you may have 100 outstanding requests and 100 execute threads, but only a few of those requests are being processed because you only have 15 listen threads.
The ration of listen threads to execute threads is controlled by the ThreadPoolPercentSocketReaders parameter, which defaults to 33(%).
As has been mentioned already, you'll need to experiment a little to optimize this. In general, you don't want an outrageous number of threads, because then there will be too much overhead. As well, most people have better luck running a separate WebLogic instance for every 1-2 CPUs in the system, rather than running a single instance with loads of threads on a many-CPU system.

[Mani Ram]

We did lot of tests and figured out the optimal value for this parameter. That was long time ago and we totally forgot about that.
Recently we upgraded the machine. We expected a good improvement in performance because of more number of CPUs & memory. But instead we faced a severe performance degradation. We almost decided to switch back to the old machine and then we realized that this setting was the reason!
But, you won't see much difference if the change in value is small. Atleast, we couldn't notice any change in performance when we changed this value in 8 to 14 range.
[ February 28, 2003: Message edited by: R Manivannan ]

[Aaron Mulder]

As for the console, I'm not sure where it is in 6.1 (don't have a 6.1 server running today), but in 7 you can access the reader percentage on the "Tuning" tab for the server, and you can configure (as well as add and remove) execute queues by right-clicking on the server name in the tree on the left and selecting the execute queues option. Hopefully it's in the same place.

[Valery Anciaux]

Thanks a lot everybody !