DFHSM0133 in EUDSA

pwdeelstra · New User Joined: 07 Jul 2009 Posts: 2 Location: Leeuwarden

We are using a CICS region with a EDSALIM of 200M. Most of this storage is used by the EUDSA part. This part is after a few hours divided in peaces of different sizes. Most of our user transactions are using 11M in the EUDSA part but when there are allocated 3 parts of 11M in the EUDSA and there are running 4 transactions which need seperate 11M, there is a DFHSM0133 in the CICS. At this moment there is no more freeEDSA but in the EUDSA there are several peaces of storage smaller then 11M available but CICS don't use this free parts of storage in the EUDSA.
How can I resolve this problem or is there no solution ?

Robert Sample · Posted: Tue Jul 07, 2009 4:30 pm

I think the question would be, what is happening to the storage? Are there any long-running transactions that grab EUDSA and don't free it? CICS allocates storage to transactions but once those transactions are done, that storage is freed for the next transaction to use.

The bigger question is what the **** is a transaction needing 11M of storage for anyway? For something that is supposed to be transient in nature, namely a CICS transaction, that's a LOT of memory!

If you don't have a free memory block large enough for the GETMAIN request, you will get storage messages. CICS does not allocate partial blocks of memory -- memory is not disk space! If you truly have to have 11M of memory, 200M of EDSA is not a lot.

I recommend you contact your site support group and work with them to review the CICS region and determine just how large EDSA needs to be for your region to handle the business needs.

pwdeelstra · New User Joined: 07 Jul 2009 Posts: 2 Location: Leeuwarden

I have already asked the development group why they are using so much storage in this transactions but I did not yet get an answer from them.
I know that I can enlarge the EDSALIM with 100M but my question was also: why doesn't CICS reshufle the storage in EUDSA because the peaces smaller then 11M are not used anymore ?

With other words: there is enough free storage in EUDSA but not the large parts (11M) which the most transactions are using !

Robert Sample · Posted: Tue Jul 07, 2009 5:43 pm

AFAIK, CICS will not do garbage collection -- if memory gets fragmented, it stays fragmented until the region is restarted. Garbage collection, from what I know, is an expensive process and the CICS developers probably didn't feel it was worth the cost to response time to implement.