Question & Answer
Question
Why am I seeing DFHTS1601 and DFHTS1602 messages for TSMAINLIMIT storage after upgrading from CICS Transaction Server for z/OS V4.1 to CICS TS V5.2? There have been no other changes to the region.
After the upgrade I started to see the following messages
DFHTS1601 Main temporary storage usage has reached 75% of TSMAINLIMIT storage.
DFHTS1601 Main temporary storage usage has reached 80% of TSMAINLIMIT storage.
DFHTS1601 Main temporary storage usage has reached 85% of TSMAINLIMIT storage.
DFHTS1601 Main temporary storage usage has reached 90% of TSMAINLIMIT storage.
DFHTS1601 Main temporary storage usage has reached 95% of TSMAINLIMIT storage.
DFHTS1602 Main temporary storage has attempted to exceed the TSMAINLIMIT
I checked my CICS system initialization (SIT) parameters and I see that I have:
TSMAINLIMIT=64M
MEMLIMIT=8G
Could it have anything to do with the TSMAINLIMIT? Is this new?
Answer
The CICS TS V4.2 documentation contains the topic New system initialization parameters with the following introduction of TSMAINLIMIT:
The TSMAINLIMIT system initialization parameter specifies a limit for the storage that is available for main temporary storage queues to use. You can specify an amount of storage in the range 1 - 32768 MB (32 GB), but this amount must not be greater than 25% of the value of the z/OS parameter MEMLIMIT. The default is 64 MB.
In versions of CICS before CICS TS for z/OS®, Version 4.2, the limit of storage available for main temporary storage queues to use was determined by the EDSALIM parameter. If your region uses a lot of main temporary storage queues, the current default TSMAINLIMIT value might not provide sufficient storage, compared with the limit determined by the previous EDSALIM value.
This is very likely a case of the TSMAINLIMIT default of 64M not being enough to handle the demands of your region. You should consider raising it. You can raise it to up to 2GB based on your MEMLIMIT definition of 8G.
See Main temporary storage: monitoring and tuning in the CICS TS 5.2 documentation for additional information about setting TSMAINLIMIT.
Product Synonym
CICS/TS CICSTS CICS TS CICS Transaction Server
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Document Information
Modified date:
08 February 2017
UID
dwa1354684