Background documentationOMS Heap Collisions Locate this document in the navigation structure

 

Explanation

This message can occur for SAP liveCache databases only.

Tasks that run in different threads attempt to request or release memory from the OMS heap in parallel. This causes an increase in the number of collisions.

User Response

Check whether the SAP liveCache database parameter OmsSubHeaps, which determines the number of OMS heap segments, has an optimum value.

Generally, the risk of collision rises with the number of processors used (MaxCPUs general database parameter). Check whether the SAP liveCache database can fulfill the requirements of the applications with fewer processors. If not, check whether the CPU on the computer is overloaded, and whether the SAP liveCache threads are blocked by other applications running on the computer. In this case, the SAP liveCache threads that contain user tasks should have received REAL TIME PRIORITY in the operating system. To avoid operating system blocks however, the value of MaxCPUs must be at least one lower than the number of actual CPUs.

More Information

Database Administration, General Database Parameters