Huge Number Of DBSNMP Sessions Impacting RAC Performance - Hundreds of Processes from pz99 to pz00, py99 to py00, etc. (Doc ID 1515385.1)

Last updated on JANUARY 18, 2013

Applies to:

Symptoms

You find there are a large number of DBSNMP sessions or processes found in your RAC database.

Performance may be degraded due to:

• Higher than normal bandwidth congestion for cluster-wide operations
• Total number of processes impacts user processes and throughput
• High memory consumption for non-user processes
• High CPU for non-user processes
• A closer inspection of the excessive processes determined
  • They are identified as owned by DBSNMP
  • The process names appear system generated starting with  pz99 ; pz98 ... and count down to pz00
  • Other processes may also show as py99 , py98 ... or even pw99 ...

Changes

None required.

The problem is unique to RAC databases.

The associated background processes are unique to multiple instance view queries (GV$).

Cause