Detector collection locking option

Products

• Detector for DB2 for z/OS
• Subsystem Analyzer for DB2 for z/OS

Issue/Introduction

How to eliminate Detector for Db2 for z/OS (PDT) serialization or change it so that it does not stop all Db2 work after collection intervals?
Is there a feature in the tool to do locking inside the address space and not under the Db2 thread?

Resolution

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

1) Set the USECOLLTASKS(Y) parameter in the PDT member of hlq.CDBAPARM. 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 for Db2 for z/OS (PSA) by (100-x)%, where x is the value selected. 

These options will:
1) Eliminate requesting the CML/LOCAL lock for the Xmanager address space by application thread running in PDT
2) Reduce the Xmanager local lock by PSA


Neither option will eliminate the use of the local lock for the Xmanager 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.