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DFHSM0133 CICS is under stress SOS above 16MB

Troubleshooting


Problem

Your CICS Transaction Server region is going short on storage (SOS) above the 16MB line. You are using the Web 3270 bridge interface and run with a fairly large EDSA value.

Cause

The garbage collection interval is too long.

Diagnosing The Problem

The DFHSM0133 SOS is caused by there being approximately 6200 web bridge tasks awaiting garbage collection. Each of these holds storage in the subpools shown using OMEGAMON® for a display of the EDSA:

Subpool name      Allocated        Used
mdttable          19156k           16773k
smshrc31          86464k           73223k
webhtml           76032k           62649k

Looking at the dump also shows that WEBDELAY is set to (5,180). This means that garbage collection will run every 3 hours and clean away data that has been unused for between 3 and 6 hours.

Resolving The Problem

Decrease the second parameter of your system initialization table (SIT) WEBDELAY setting to reduce the storage used by having garbage collection done more frequently.

The recommendation is to drastically reduce the garbage collection interval. Change WEBDELAY to something like (5,20), the default is (5,60). This will cause garbage collection to run every 20 minutes and for data to be around for at most 40 minutes instead of 6 hours (as was the case with the WEBDELAY setting at 5,180). Then monitor the effects and adjust WEBDELAY as necessary. You need to find a good balance between the frequency of garbage collection and the high water mark for storage being used by Web bridge tasks.

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Product Synonym

CICS/TS CICS TS CICS Transaction Server CICS/VSE VSE z/VSE

Document Information

Modified date:
05 January 2026

UID

swg21217260