Question & Answer
Why am I receiving message DFHSM0131 CICS is under stress (short on storage below 16MB)? My CICS region just started getting intermittent SOS below the line in the UDSA. I am running CICS Transaction Server for z/OS (CICS TS) 3.2 and software from vendor GT Software.
The vendor GT Software was contacted and supplied a new version of the GIICALS module which resolved the DFHSM0131, short on storage condition.
Reviewing a dump taken at the time of the SOS condition, you will see the UDSA is using the majority of the below the line storage. To format the Storage Manager domain, enter VERBX DFHPDxxx 'SM=1 (where xxx is your release level of CICS like 690 for CICS TS 5.2). Here is an example from the SM domain:
Current DSA limit: 8192K Current DSA total: 8192K Currently SOS below 16M: YES
Here is the breakdowon of the below the line DSAs:
UDSA Summary Size: 6912K CDSA Summary Size: 768K SDSA Summary Size: 256K RDSA Summary Size: 256K
The UDSA is utilizing the majority of the below the line DSA. It only contains user task storage - USER24, with storage accounting beginning with B00xxxxx, where xxxxx is the task number.
Looking at the Task subpool summary, you see 4 tasks using about 1508K each.
Name Tran Loc Pagestg B0000048 GN2W B 1508K B0000049 GN2W B 1508K B0000053 GN2W B 1532K B0000054 GN2W B 1532K
Looking at the storage elements under these tasks, you will find a commonality- each storage element has many, many x'B0' elements allocated to them. Here is an example:
SCE.B0000048 2244A740 Storage Element Descriptor 0000 2244A7E8 22448B78 002F79A0 000000B0 <---length |address
These areas mainly contain zeros and some addresses.
In the dump I was looking at, it had a large internal trace and captured a few of these getmain requests. To format the CICS trace, enter VERBX DFHPDxxx 'TR=1 (where xxx is your release level of CICS like 690 for CICS TS 5.2).
ENTRY - FUNCTION(GETMAIN) GET_LENGTH(98) SUSPEND(YES) EXIT - FUNCTION(GETMAIN) RESPONSE(OK) ADDRESS(00422378)
Next I entered option 1 from the IPCS primary option menu to Browse the dump data set and found that the return address for the getmain pointed to vendor module GIICALS from GT software. Here is the eyecatcher:
|** DCCKICS - CICS Entry | | ****** Copyright by GT Softw| |are, Inc. ****** All Rights | |reserved! ****** As| |sembled for ZOS ****** |
CICS/TS CICSTS CICS TS CICS Transaction Server
03 March 2015