This site will undergo a maintenance outage on Saturday, 13 September beginning at 2:30 AM Central/1 PM IST for a platform upgrade. The downtime will be ~three hours.

Analyze lock problems

To analyze lock problems, start with the PI Region Lock Wait List view (IPIRGWT).

The IPIRGWT view displays a list of all regions that are waiting for a resource lock, and it provides information about the resource and the region causing the lock contention. The view is sorted by descending wait time to highlight waiting regions that are most impacted.

You can determine the cause of a wait by examining the ultimate holder information in the IPIRGWT view. If there is only one ultimate holder, its region ID and jobname are displayed.

Related topic

Analyze-program-isolation-lock-contention


Note

If a waiting region has requested an exclusive lock for a resource held by several regions with shared locks, there will be multiple ultimate holders in the Cnt Ult field. In that case, you should hyperlink from the Cnt Ult field to access the PI Region Lock List view (IPIRGLST), which lists the ultimate holders of a resource.

The resource in contention is identified in the IPIRGWT Database Name field (to the right in the view). You may need to know how many other regions are waiting for the resource to understand the impact of the resource contention. You can hyperlink on the Database Name field to access a list of all regions waiting for the resource in the PI Resource Lock Wait List view (IPIRSWT).

A resource wait cannot be resolved until the ultimate holder region releases the resource. The resource might not be released until the program issues its next sync point, which may be when the program finishes execution. If you have the BMC AMI Ops Automation for IMS implemented, you can issue the P or PA command from the IPIRGWT view to stop the ultimate holder region, but you should determine the impact of doing so before you proceed.

To determine the impact of stopping an ultimate holder region, check the Ultimate Held field on the IPIRGLST view to find out how many resources are being held by the region. If the number is low, stopping the region will have less impact. If the number is high, you should consider increasing the region’s performance level so that it can complete processing sooner, rather than issuing a stop region command.

Note

For more information about the P and PA actions, see Line-commands-program-isolation-lock-views.

 

Tip: For faster searching, add an asterisk to the end of your partial query. Example: cert*