Set the ulimit values on UNIX and Linux operating systems

Setting the appropriate ulimit values on your UNIX or Linux operating system can affect how IBM® Cognos® Analytics performs.

For example, on Linux® operating systems, problems that are caused by stack ulimit settings include unusually high memory usage of BIBusTKServerMain or BIBusTKServerMain errors when large reports are processed.

If you are using the report service on Linux operating systems, running reports or idle BIBusTKServerMain processes can use all of your available RAM.

Whereas, on UNIX operating systems, issues can arise if the stack ulimit settings are too low.

Ensuring the correct stack ulimit settings can prevent these problems.

The recommended ulimit settings for a new installation are as follows:

IBM AIX®
  • CPU time (seconds): ulimit -t unlimited
  • File size (blocks): ulimit -f unlimited
  • Maximum memory size (kbytes): ulimit -m unlimited
  • Maximum user processes: ulimit -u unlimited
  • Open files: ulimit -n 8192 (minimum value)
  • Stack size (kbytes): ulimit -s 8192 (minimum value)
  • Virtual memory (kbytes): ulimit -v unlimited
Linux (x, z, and p)
  • CPU time (seconds): ulimit -t unlimited
  • File size (blocks): ulimit -f unlimited
  • Maximum memory size (kbytes): ulimit -m unlimited
  • Maximum user processes: ulimit -u unlimited
  • Open files: ulimit -n 8192 (minimum value)
  • Stack size (kbytes): ulimit -s unlimited
  • Virtual memory (kbytes): ulimit -v unlimited
Note: These settings may need to be adjusted for your environment during the lifecycle of the application.