IMS-related problems

Use this topic to investigate, and resolve problems with IMS and IBM® MQ..

This topic includes plans for the following problems that you might encounter in the IMS environment:

IMS cannot connect to IBM MQ

Problem
The IMS adapter cannot connect to IBM MQ.
Symptoms
IMS remains operative. The IMS adapter issues these messages for control region connect:
  • CSQQ001I
  • CSQQ002E
  • CSQQ003E
  • CSQQ004E
  • CSQQ005E
  • CSQQ007E
For details, see the IBM MQ for z/OS® messages, completion, and reason codes documentation.

If an IMS application program tries to access IBM MQ while the IMS adapter cannot connect, it can either receive a completion code and reason code, or terminate abnormally. This depends on the value of the REO option in the SSM member of IMS PROCLIB.

System action
All connection errors are also reported in the IMS message DFS3611.
System programmer action
None.
Operator action

Analyze and correct the problem, then restart the connection with the IMS command: 


/START SUBSYS subsysname

IMS requests the adapter to resolve in-doubt units of recovery.

IMS application problem

Problem
An IMS application terminates abnormally.
Symptoms

The following message is sent to the user's terminal: 


DFS555I  TRANSACTION tran-id ABEND abcode
MSG IN PROCESS: message data:

where tran-id represents any IMS transaction that is terminating abnormally and abcode is the abend code.

System action
IMS requests the adapter to resolve the unit of recovery. IMS remains connected to IBM MQ.
System programmer action
None.
Operator action
As indicated in message DFS554A on the IMS master terminal.

IMS is not operational

Problem
IMS is not operational.
Symptoms
More than one symptom is possible:
  • IMS waits or loops

    IBM MQ cannot detect a wait or loop in IMS, so you must find the origin of the wait or loop. This can be IMS, IMS applications, or the IMS adapter.

  • IMS terminates abnormally.
    • See the manuals IMS/ESA® Messages and Codes and IMS/ESA Failure Analysis Structure Tables for more information.
    • If threads are connected to IBM MQ when IMS terminates, IBM MQ issues message CSQ3201E. This message indicates that IBM MQ end-of-task (EOT) routines have been run to clean up and disconnect any connected threads.
System action
IBM MQ detects the IMS error and:
  • Backs out in-flight work.
  • Saves in-doubt units of recovery to be resolved when IMS is reconnected.
System programmer action
None.
Operator action
Resolve and correct the problem that caused IMS to terminate abnormally, then carry out an emergency restart of IMS. The emergency restart:
  • Backs out in-flight transactions that changed IMS resources.
  • Remembers the transactions with access to IBM MQ that might be in doubt.
You might need to restart the connection to IBM MQ with the IMS command:

/START SUBSYS subsysname

During startup, IMS requests the adapter to resolve in-doubt units of recovery.