Xmanager short of above the bar memory PXM0372 SHORTAGE THRESHOLD MOBJ

Products

• Detector for DB2 for z/OS
• Subsystem Analyzer for DB2 for z/OS
• Database Management for DB2 for z/OS - Administration Suite
• Database Management for DB2 for z/OS - Performance Suite
• Database Management for DB2 for z/OS - Recovery Suite
• Database Management for DB2 for z/OS - SQL Performance Suite
• Database Management for DB2 for z/OS - Utilities Suite
• DATABASE MANAGEMENT SOLUTIONS FOR DB2 FOR Z/OS

Issue/Introduction

Executing Detector for Db2 for z/OS (PDT) and just put a new maintenance package into our test system and noticed the following messages in the task log:

Do not use any zIIP processors in the XMANAGER task.
PXM0372 XMANAGER REGION INUSE HAS REACHED SHORTAGE THRESHOLD FOR MOBJ
PROBLEM Reason: SHORT OF ABOVE THE BAR MEMORY
PSA0171 SSANALZE COLLECTION INTERVAL END FORCED DUE TO XMANAGER STORAGE SHORTAGE

Cause

PXM0372 XMANAGER REGION INUSE HAS REACHED SHORTAGE THRESHOLD FOR MOBJ

The above message is an indication that the current MEMLIMIT is not enough. 

Xmanager will initiates region shutdown and: 

1 - Detector and Subsystems Analyzer collections will terminate the current interval, 
making it shorter than the specified interval hour. 

2 - Detector and Subsystems Analyzer collections will externalize the data collected for 
that short interval to Detector/Subsystem Analyzer datastore as it normally does. 
When an interval starts, PDT and PSA allocates storage as it needs. 
When interval ends and a new interval starts, PDT and PSA start collecting data for the new interval. 
In the meantime, it writes out the data collected on previous interval to the datastore if externalization 
is chosen and then free the storage used in last interval. 
So the storage usage at interval end may look higher until the storage of previous interval is freed. 
There is no data loss. 

3 - Xmanager will free up the storage and start a new interval. 

Resolution

Ideas to help resolve the situation:

1 - Increase the MEMLIMIT to a higher value than your current value of 4G and monitor the situation. 

2 - Shorten the collection interval from 1 hour to possibly 30 minutes if MEMLIMIT needs more auxiliary 
storage than you want to set. 

3 - Evaluate the need to collect all table/index statistics for all dynamic SQL statement. This is controlled by
include/exclude collection profile with DTB(Y/N). Turning DTB to 'N' in the collection profile lessens the storage requirement. 

4 - Evaluate the need to collect all Dynamic SQL TEXT statistics. SQLT(N) will disable additional SQL text collection
used to collect resource statistics associated with dynamic SQL statements.