During Heavy Batch Jobs sun cluster diskgroup monitoring causing hang with enq: DD - contention

(Doc ID 1537179.1)

Last updated on MARCH 13, 2013

Applies to:

Oracle Database - Enterprise Edition - Version and later
Information in this document applies to any platform.


2 node RAC Cluster (Oracle Cluster built on top of a Sun Cluster) in Production M9000 Machine.
Whenever batch jobs run with multiple threads (which also does a lot of i/o), then there is a build up of "enq: DD - contention Waits" processess in the ASM Instance
and these processess never die and they keep on building up.
When these "enq: DD - contention Waits" processess exceeds the processess value, then it is hitting ORA-00020 Error
and the database goes to hang state, as it does not allow any other new processess.

Once the application batch jobs finish, then these "enq: DD - contention Waits" processess will die away on their own and the system returns to normalency.


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