PCF responses in IBM MQ

In response to each command, the command server generates one or more response messages. A response message has a similar format to a command message.

The PCF header has the same command identifier value as the command to which it is a response (see MQCFH - PCF header for details). The message identifier and correlation identifier are set according to the report options of the request.

If the PCF header type of the command message is MQCFT_COMMAND, standard responses only are generated. Such commands are supported on all platforms except z/OS . Older applications do not support PCF on z/OS ; the IBM MQ Windows Explorer is one such application (however, the Version 6.0 or later IBM MQ Explorer does support PCF on z/OS ).

If the PCF header type of the command message is MQCFT_COMMAND_XR, either extended or standard responses are generated. Such commands are supported on z/OS and some other platforms. Commands issued on z/OS generate only extended responses. On other platforms, either type of response might be generated.

If a single command specifies a generic object name, a separate response is returned in its own message for each matching object. For response generation, a single command with a generic name is treated as multiple individual commands (except for the control field MQCFC_LAST or MQCFC_NOT_LAST). Otherwise, one command message generates one response message.

Certain PCF responses might return a structure even when it is not requested. This structure is shown in the definition of the response ( Definitions of the Programmable Command Formats ) as always returned. The reason that, for these responses, it is necessary to name the objects in the response to identify which object the data applies.


Message descriptor for a response

A response message has the following fields in the message descriptor:

    MsgType
    This field is MQMT_REPLY.

    MsgId
    This field is generated by the queue manager.

    CorrelId
    This field is generated according to the report options of the command message.

    Format
    This field is MQFMT_ADMIN.

    Encoding
    Set to MQENC_NATIVE.

    CodedCharSetId
    Set to MQCCSI_Q_MGR.

    Persistence
    The same as in the command message.

    Priority
    The same as in the command message.

The response is generated with MQPMO_PASS_IDENTITY_CONTEXT.

Parent topic: Use IBM MQ Programmable Command Formats