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DFHSM0131 CICS SOS below 16MB when using GT Software

Question & Answer


Question

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.

Answer

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         ******  |


[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSGMGV","label":"CICS Transaction Server"},"Platform":[{"code":"PF035","label":"z\/OS"}],"Component":"SOS","Version":"","Line of Business":{"code":"LOB17","label":"Mainframe TPS"}}]

Product Synonym

CICS/TS CICSTS CICS TS CICS Transaction Server

Document Information

Modified date:
03 March 2015

UID

dwa1177781