Detector collection locking option

Document ID : KB000015636
Last Modified Date : 14/02/2018
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Question:

How to eliminate serialization or change it so that it doesn’t stop all DB2 work after collection intervals? Is there a feature in the tool to do locking inside address space and not under the DB2 thread?

Answer:

There are two ways to reduce the locking at interval end: 

1) Set the USECOLLTASKS(Y) parm in the PDT parmlib. With the exception of PREPARE statements, this will eliminate all locking underneath the allied thread for Detector collections. 

2) On the Subsystem Analyzer startup panel, there is a new option, Sampling Rate. Setting the sampling rate will reduce the locking done in Subsystem Analyzer by (100-x)%, where x is the value selected. 

Those options will

1) Eliminate requesting the CML/LOCAL lock for the XMAN address space by application thread running in Detector, and

2) Reduce set the XMAN local lock by subsystem analyzer,

but neither option will eliminate the use of the local lock for the XMAN address space.

Note though, there is no locking of any of the DB2 address spaces nor is there any lock requests for the allied thread.