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IBM Cognos 8 Platform => COGNOS 8 => COGNOS 8 Administration => Topic started by: mariorubbo on 10 Jun 2010 06:50:24 AM

Title: maximum number of report processes
Post by: mariorubbo on 10 Jun 2010 06:50:24 AM
At one time, I would manipulate this number based on the number of CPU on a machine, but at the Cognos Forum in 2009 one of the presenters talked about his environment and mentioned that this setting didn't need to be modified because C8 would automatically detect the number of CPU's on a machine and multiply that number by the maximum number of report processes.  I've since been rereading that I should modify this number manually to reflext the number of CPU's.

Does everyone modify this number manually?  Has anyone else been confused?
Title: Re: maximum number of report processes
Post by: MFGF on 10 Jun 2010 07:08:12 AM
Wow - that really is conflicting and misleading information.  Cognos 8 does not interrogate the OS to determine how many CPUs/cores are available, and cannot automatically modify the number of report processes to suit.  Either the message at Forum 2009 was misunderstood, or the presenter was mistaken.

Maybe he was referring to the maximum number of concurrent reports which can be run, which is the number of defined low affinity connections multiplied by the number of defined report services?  Still, both of these do need to be set manually by the administrator, so I have absolutely no idea where the concept of auto-detection came from.

Hope that helps!

MF.
Title: Re: maximum number of report processes
Post by: mariorubbo on 10 Jun 2010 07:15:50 AM
Thanks, MF.  I'm going back to modifying this number manually.  This also dovetails into my other post about the amount of RAM that can be utilizied by BI on an App server.  I had picked up somewhere that the heap memory was divided up between java.exe and the BIBus executables.  I had also read that 2GB was a practical limit for the heap so I've been recommending 4GB machines.  Based on that assumption, a machine with 8GB would be underutilized from a RAM perspective and there was no performance benefit in increasing the heap size via Cognos Configuration.  I've recently begun hearing that each BiBUS can have its own 2GB memory space in addition to the 2GB for java.exe.  If so, and I increase the number of report processors beyond 2, then the rule of thumb that each CPU should have 2GB of RAM makes a little more sense.
Title: Re: maximum number of report processes
Post by: CognosPaul on 31 Jul 2010 04:20:22 PM
Hello HelenJames,

I'm afraid you have failed the Turing test. Please understand that, while I remove your posts and request your banishment, I hold no grudge against you or your robotic cohorts. I will ask you to kindly refrain from making any further automated postings until you are banned.

Thank you
Title: Re: maximum number of report processes
Post by: Alp on 02 Aug 2010 01:08:17 AM
Regarding memory utilization limit.

There is a known JVM 32 limitation regarding memory heap size on Windows. I guess it is about 1.5 GB. My guess would be that going above 1.5 would require 64 bit Cognos, in fact that is 64 bit JVM that does the trick. 

- Alp
Title: Re: maximum number of report processes
Post by: joe123 on 02 Aug 2010 06:13:57 AM
I remember the limit for the JVM is around 1152 MB.
Just take a look to the cognos proven practices, especially to the performance section.

http://www.ibm.com/developerworks/data/library/cognos/cognosprovenpractices.html