When CICSPlex® SM doesn’t seem to be responding, you should suspect a stall condition, which could be either a
loop or a wait.
Note:
In the case of a suspected loop or wait, you should request
an SDUMP; CICSPlex SM will not take one automatically. However, do not cancel
the task that appears to be stalled before requesting the dump. If you cancel
the task, the CICS® and CICSPlex SM recovery routines that get control will
change the "picture" taken by the dump and you may lose valuable diagnosis
information.
You will need to determine both at what stage of processing the stall occurred
and where it occurred. Processing a CICSPlex SM request involves multiple address
spaces. The process could stall in the TSO/ISPF session, in any of the CICS systems
included in the current context and scope, or at any of several points in
between.
Use the information in this section to help you isolate the cause of a stall or to report the condition to customer support
personnel.
- Questions to ask
-
- Did the stall occur during initialization?
- How far did initialization progress?
- Were there any definition or setup errors reported?
- Did the stall occur during operation?
- Are the necessary communication links between CASs, CMASs, and MASs
available?
- What type of request was being processed?
- How big was the CICSplex involved?
- How many CMASs and MASs were involved?
- What types of monitoring, real-time analysis, and workload management were active?
- Did the stall occur during termination?
- Did the stall occur in the ISPF end-user interface?
- Did the stall occur in a CAS?
- Did the stall occur in a CMAS?
- Did the stall occur in a MAS?
Try stopping the MAS agent code (using
the STOP action command from the MAS view), then evaluate the underlying CICS system.
- Is the CICS system taking an SDUMP?
- Is the CICS system looping or hung?
- Did the request time out with a CICS message?
- Is the CICS system experiencing a short on storage (SOS) condition,
or has it reached its MAXTASK level?
Any one of these conditions could prevent some types of CICSPlex SM requests
from completing.
- Documentation to collect
-
- System console log and EYULOG
- CAS and CMAS job logs
- Unformatted SDUMP from the affected address spaces (TSO, CAS, CMAS or MAS)
- Questions to ask
-
- What are some possible sources of the loop?
- Is CPU usage particularly high?
- Documentation to collect
-
- Appropriate job logs
- Selected trace data, as requested by support
- AUXTRACE data set, if available
- Transaction dump, if any
- CICS system dump, if any
- Questions to ask
-
- At what point is the wait occurring?
- Is CPU usage particularly low?
- Documentation to collect
-
- Appropriate job logs
- Appropriate CICS CEMT queries
- Selected trace data, as requested by support
- AUXTRACE data set, if available
- Transaction dump, if any
- CICS system dump, if any
An unformatted dump is the preferred source of problem diagnosis information
for a stall. You should format a CICSPlex SM dump only at the request of customer
support personnel.
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