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CESC transaction looping in CICS when running with CA ACF2

Question & Answer


Question

Why would the CESC transaction loop in my CICS Transaction Server for z/OS (CICS TS) region for no apparent reason? I don't know of anything in my CICS region that would lead to a loop and there have been no changes to the CESC transaction definition. I use CA ACF2 from CA Technologies for security.

Answer

Diagnosis showed there was a loop of CA modules that manifested itself in the CESC transaction looping, doing GETNEXT TCTE ENTRY and EXIT's in the CICS Internal trace. CESC is a victim of a storage overlay in the ECDSA subpool ZCTCTTEL which is causing the loop. The overlay is caused by CA ACF2. Per the CA software engineer:

If you use ACF2EXIT you have to rewrite the exit using command level using the sample from samplib and apply the follow PTFs or ACF2 R15 will cause a storage overlay due to the change in CICS TS 4.2

It was recommended to that you apply CA PTF RO73740. This maintenance has the following prerequisites (PREs):

RO46083
RO49397
RO53745
RO59229
RO69515
RO71103

Loops can sometimes reveal themselves in the system trace (SYSTRACE). To make sure this is your problem, you will need a system dump of the CICS region at the time of the loop. You can enter IPCS command IP SYSTRACE to display the system trace. In this particular case, I saw that there was a loop of Estae and Time requests occurring for the TCB that the CESC transaction was running on. There were pages and pages of the trace entries like this:

 01 00XX 009F81B0  SVC     3C 00000000_133AC3C8 Estae
                              07040000 80000000
 01 00XX 009F81B0  SVCR    3C 00000000_133AC3C8
                              07040000 80000000
 01 00XX 009F81B0  SVC      B 00000000_133A2124 Time
                              07042000 80000000
 01 00XX 009F81B0  SVCR     B 00000000_133A2124
                              07042000 80000000
 01 00XX 009F81B0  SVC     3C 00000000_133ABDAA Estae
                              07040000 80000000
 01 00XX 009F81B0  SVCR    3C 00000000_133ABDAA
                              07040000 80000000
 01 00XX 009F81B0  SVC     3C 00000000_133AC3C8 Estae
                              07040000 80000000
 01 00XX 009F81B0  SVCR    3C 00000000_133AC3C8
                              07040000 80000000
 01 00XX 009F81B0  SVC      B 00000000_133A2124 Time
                              07042000 80000000
 01 00XX 009F81B0  SVCR     B 00000000_133A2124
                              07042000 80000000
 01 00XX 009F81B0  SVC     3C 00000000_133ABDAA Estae
                              07040000 80000000
 01 00XX 009F81B0  SVCR    3C 00000000_133ABDAA 

This was a yielding loop, that occasionally was interrupted. The PSW for all these addresses pointed within:

 | .00..GCSLIO...}. |
 | ........&J..&... |
 | .J...0{.GCSLIO L |
 | JT3301 04.10 03/ |
 | 17/08 (C)1992,20 |
 | 08 COMPUTER ASSO |
 | C. INTL, INC .ST |
 | RPATCH{.{.{:{@{= |
 
 | &0....A.....TRAC |
 | FAIL GCSLIO ESTA |
 | E FAILED...0F-8. |

It would occasionally be interrupted by Getmains and TestAuth's :

 01 00XX 009F81B0  SVC     78 00000000_1352F0FC  Getmain
                              07040000 80000000
 01 00XX 009F81B0  SVCR    78 00000000_1352F0FC
                              07040000 80000000
 01 00XX 009F81B0  SVC     77 00000000_1352F140  TestAuth
                              07041000 80000000

These pointed into a CA module with these eyecatchers:

 | {.wGCSLOP LJT330 |
 | 1 12.38 06/25/07 |
 |  (C)1992,2007 CO |
 | MPUTER ASSOC. IN |
 | TL, INC STRPATCH |

Contact CA Technologies if you need additional assistance.

Andre Clark, CICS Level 2 Support

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Product Synonym

CICS/TS CICSTS CICS TS CICS Transaction Server

Document Information

Modified date:
18 February 2016

UID

dwa1251730