Has there been an abend?

Use this topic to investigate common causes of abends and the different types of abend that can cause problems.

If the application has stopped running, it can be caused by an abnormal termination (abend).

You are notified of an abend in one of the following places, depending on what type of application we are using:

    Batch
    Your listing shows the abend.

    CICS
    You see a CICS transaction abend message. If your task is a terminal task, this message is displayed on your screen. If your task is not attached to a terminal, the message is displayed on the CICS CSMT log.

    IMS
    In all cases, you see a message at the IBM MQ for IMS master terminal and in the listing of the dependent region involved. If an IMS transaction that had been entered from a terminal was being processed, an error message is also sent to that terminal.

    TSO
    We might see a TSO message with a return code on your screen. (Whether this message is displayed depends on the way the system is set up, and the type of error.)


Common causes of abends

Abends can be caused by the user ending the task being performed before it terminates normally; for example, if you purge a CICS transaction. Abends can also be caused by an error in an application program.


Address space dumps and transaction dumps

For some abends, an address space dump is produced. For CICS transactions, a transaction dump showing the storage areas of interest to the transaction is provided.

  • If an application passes some data, the address of which is no longer valid, a dump is sometimes produced in the address space of the user. Note: For a batch dump, the dump is formatted and written to SYSUDUMP. For information about SYSUDUMPs, see SYSUDUMP information on z/OS. For CICS, a system dump is written to the SYS1.DUMP data sets, as well as a transaction dump being taken.
  • If a problem with IBM MQ for z/OS itself causes an abend, an abend code of X'5C6' or X'6C6' is returned, along with an abend reason code. This reason code uniquely describes the cause of the problem. See IBM MQ for z/OS abends for information about the abend codes, and see Return codes for an explanation of the reason code.


Abnormal program termination

If your program has terminated abnormally, see Dealing with abends on IBM MQ for z/OS.

If the system has terminated abnormally, and we want to analyze the dump produced, see IBM MQ for z/OS dumps. This section tells you how to format the dump, and how to interpret the data contained in it.

Parent topic: Making initial checks on z/OS