COGNOS JAVA HEAP SIZE

[sdf]

Hi,

I hope someone could help me.
I just want to know the best practice for setting the heap size in cognos configuration.
All i know is that if the heap for jvm is set too high the process wouldn't start.
For some other applications we have the practice to set the heap size to 50% of the total RAM of the server.
But we have a case that users are reporting slowness when running reports.
I would like to understand how we can identify into how much heap to set and what are the considerations.

[MFGF]

Hi,

I hope someone could help me.
I just want to know the best practice for setting the heap size in cognos configuration.
All i know is that if the heap for jvm is set too high the process wouldn't start.
For some other applications we have the practice to set the heap size to 50% of the total RAM of the server.
But we have a case that users are reporting slowness when running reports.
I would like to understand how we can identify into how much heap to set and what are the considerations.

Does this help?

http://www-01.ibm.com/support/docview.wss?uid=swg21587457

Cheers!

MF.

[sdf]

Wow, thanks MF.
This helps.

But, in cognos configuration, the maximum memory in MB is already set to 8192 MB. Still experiencing slowness.
In the link you provided, it was mentioned that the Heap size was set to minimum and maximum. Is this done in the xml file?

Thanks!

[AussiePete2011]

Hi there

I'd actually suggest that you turn on performance monitoring to see where the delay is.
See the following thread.  Although it's referencing 8 it's also relevant to 10.
http://www.cognoise.com/index.php?topic=14095.0

This will give you a better idea about the underlying reasons and then you can decide if it's memory or SQL or backend.

Cheers
AussiePete

[sdf]

Hi Pete,

Thanks for the reply.
I did the steps you provided in the other thread but i am not able to produce the performance log file.
Also tried,

instead of :
<category name="Perf.QFS" class="com.cognos.indications.LogTypedLogger">
      <level value="info"/>

i tried this :
<category name="Perf.QFS" class="com.cognos.indications.LogTypedLogger">
      <level value="warn"/>

But still no log files were produced.


By the way, Cognos is on version 10.2.1 with FP3

[AussiePete2011]

Hi there

It needs to be

<category name="Perf.QFS" class="com.cognos.indications.LogTypedLogger">
<level value="debug"/>
</category>

Debug will breakdown the component level timing.

This is a relevant document as well - http://www.ibm.com/developerworks/data/library/cognos/infrastructure/cognos_specific/page529.html

I'll see what else I can dig up.  Just be aware though that setting this will stop audit logging into your Audit database for the duration of the trace.

Cheers
AussiePete

[AussiePete2011]

Another cool resource
http://www.ibm.com/developerworks/library/ba-pp-performance-cognos10-page646/index.html