How to trigger a BIBusTKServerMain process OOM

[Eag. E]

Hi Gurus,

My customer is based on 10.1 (CQM only) on Linux, recently they have got "Out Of Memory" issue, as system is CQM only, we suspected that this is due to 32bits limitation of BIBusTKServerMain for each process.

The issue is only happened with few of reports recently (they were good before), the only difference is that customer has more and more data in their warehouse DB. So could you please guys tell me how Cognos allocate memory (whatever 2GB or 3GB for BIBusTKServerMain's process), is there some formula to calculate the memory allocation so that we could set a BIBus process' limitation? 

Thanks

Eag.

[Eag. E]

Or let me be more clear. How to manually generate a BIBusTKServerMain OOM issue, is that possible ?>That is a good way to understand how Cognos works, isn't it

[smiley]

When choosing for CQM you indeed limit yourself to 32 bits technology, thus 2/3 gig memory per bibus.
If you manage to run 1 report inside that bibus that requires more then 2/3 gig, you´re done.

To manage this under 3 gig, you need to limit the number of concurrent reports per bibus process to make sure the full 2/3 gig is available.
Then you manage the number of bibusses themselves, according to your available hardware specs.
Assuming ad-hoc reporting executed during the day, the value for the number of bibusses themselves is:
- Maximum number of processes for the report service during peak period. (default = 2)

The value for the number of maximum concurrent report requests per bibus is:
-  Number of low affinity connections for the report service during peak period (default = 8 )

Basically the default nr of low affinity value of 8, assumes that your reports do not consume a lot of memory. (2000/8 = 250mb)
You can enlarge number of processes, and lower the number low affinity requests to have more memory per report.

edit; with your version 10.1 the default number of low affinity could be 4.
It changed to 8 in one of the newer versions to be better suited for DQM.