CICS

Please define when the resources override YAML file is loaded into CICS from the USSCONFIG directory, and when (if at all) the previously loaded file is preserved across CICS system restarts.  Is it like this:  a CICS region INITIAL start loads the file afresh from USSCONFIG, but a warm start resumes using the previous version of the overrides YAML file (that has been saved in the CICS catalog perhaps).

If the resources override YAML file is preserved across CICS restarts (say in the CICS catalog), is there a method of viewing that copy?

Hi Reuben,

The resource overrides YAML file is not "recovered/preserved" from one CICS execution to the next CICS execution.
Though, of course, if the content of the USSCONFIG directory (namely the same feature toggles and resource overrides file) are unchanged then the same overrides would continue to be in affect.

If overrides are opted in using the feature toggle, the CICS Resource Overrides file is loaded on every CICS startup (regardless of the start type, be it initial / auto etc..). It is the content of that overrides file that will be used for new CICS resources being installed, during that lifetime of CICS.

If CICS is re-started (eg warm start) it will again read the content of the overrides file residing in USSCONFIG. And it is that contents of this overrides file that will be used for any further resources being installed.

(Changing the contents of the overrides file during the lifetime of CICS will not change the overrides in affect during that lifetime of CICS, until CICS is restarted)
Further information can be found here https://www.ibm.com/support/knowledgecenter/SSGMCP_5.6.0/configuring/resources/resource-definition-overrides.html


This should not be confused with the CICS resources themselves. If a CICS resource is installed and catalogued - on a future warm/emergency start of the region it would be recovered from the catalog. This is not considered a new install of the resource, rather a recovery of the prior resource state. If that CICS resource is then deleted and reinstalled - that would be a new CICS resource install and subject to any overrides loaded in the CICS system.