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Resolving DISPATCH OPENPOOL waits in CICS by finding tasks that own open TCBs

Question & Answer


Question

The Dispatacher domain in my CICS dump shows tasks waiting on resource DISPATCH OPENPOOL. This means tasks are waiting for open TCBs to become available. How can I tell which tasks currently own the open TCBs in my CICS region?

Answer

Format the Dispatcher domain summaries with VERBX DFHPDxxx 'DS=1' (where xxx is your release level of CICS like 690 for CICS TS 5.2).

I usually MAX to the bottom (enter M followed by F8 key), then page backwards to see the Open TCBs summary. You could also enter a FIND command on 'OPEN TCBS'. The Open TCBs summary looks something like this:

alt text

This summary shows all of the open TCBs (L8 or L9 TCBs) that are currently allocated to tasks. The task number is the last 5 numbers in the XM_TXN_TOKEN (prior to the C).

From this example, it is task #'s 15118, 11184, 15120 and 15115 that own open TCBs. You can determine the associated transaction IDs for these tasks by formatting the Kernel domain (enter VERBX DFHPDxxx 'KE=1') and searching on each of the task #'s.

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSGMGV","label":"CICS Transaction Server"},"Platform":[{"code":"PF035","label":"z\/OS"}],"Component":"Dispatcher","Version":"","Line of Business":{"code":"LOB35","label":"Mainframe SW"}}]

Product Synonym

CICS/TS CICSTS CICS TS CICS Transaction Server

Document Information

Modified date:
16 December 2014

UID

dwa1167595