Date:         Fri, 29 Aug 1997 07:30:54 -0500
Reply-To:     CICS List <CICS-L@UGA.CC.UGA.EDU>
Sender:       CICS List <CICS-L@UGA.CC.UGA.EDU>
From:         John Chase <jchase@ALS.AMERITECH.COM>
Organization: Ameritech Library Services
Subject:      Re: Help w/ R34
Content-Type: text/plain; charset=us-ascii

reboot wrote:
>
>  New to CICS troubleshooting problem w/ these symtoms
>
> Getting abends w/ what appears to be 3rd party software .  Syslog shows
> 'Protection Exceptions' anywhere from 3-8 hours after log shows storage
> violations.
 
Which version of CICS?  Which operating system?  What kind of software
(application, "system" utility, performance monitor, etc.)?  In what
programming language is it written?
 
> Q1 Is the storage violation overwriting memory and the abends happening when
> a 'sleeping' app goes back and tries to reference that area?
 
"Storage violation" refers to an application (usually) writing into
storage not allocated to its task, corrupting one or more Storage
Accounting Areas in the process, within the CICS region/partition.  The
violation is detected by CICS when a FREEMAIN (usually; can also be
detected at GETMAIN time if a FAQE is corrupted) is processed.
"Protection exception" (aka S0C4) usually refers to a task attempting to
write (or sometimes read) storage in another address space, and is
detected by the operating system.  A storage violation can certainly
precipitate a S0C4 at any later time.
 
> Q2 The sdump file's last lines show a getmain() 3ac and then freemain()
> 79650, is a program accessing this address then freeing up to much space
> causing the abend.
 
Sounds like it may be trying to FREEMAIN somebody else's storage.
 
> Q3 Is it possible to 'manually' create a dump file?
 
Issue CEMT PERFORM SNAP at the console (ensure your dump dataset is
large enough to hold the entire CICS region/partition).  Refer to the
manual "CICS Supplied Transactions" for details.
 
> That is dump all memory
> contents to a file to see what is where.  IE run an app, check memory, run
> app2 and see what addresses have changed by comparing files?
 
The mere fact that some addresses have changed between dump1 and dump2
is unlikely to reveal that a storage violation occurred.  See the "CICS
Problem Determination" manual for explanations of how storage violations
can be caused and detected, and for some techniques on tracking down the
causes, diagnosing the dump, etc.
 
John Chase
Systems Engineer
NOTIS Support Center
 
>
> Any replies are greatly appreciated....