ConnTag (MQBYTE128) on IBM MQ for z/OS

. A connection tag is conceptually similar to a connection identifier, but might span multiple related connections, identifying them as a single application instance. On IBM MQ for z/OS, the connection tag is an input field, provided by the application and used in conjunction with MQCNO_*_CONN_TAG options to serialize connections from that application instance

Where there are multiple instances of an application that are intended to be simultaneously connected, they must each supply a unique value for this field. See the descriptions of these connection tag options for further details.Notes:

  • On IBM MQ for z/OS, there is no way to administratively determine the connection tag associated with an application at runtime.
  • Connection tag values beginning with MQ in upper, lower, or mixed case in either ASCII or EBCDIC are reserved for use by IBM products. Do not use connection tag values beginning with these letters.

Use the following special value if you require no tag:

    MQCT_NONE
    The value is binary zero for the length of the field.

    For the C programming language, the constant MQCT_NONE_ARRAY is also defined; this constant has the same value as MQCT_NONE, but is an array of characters instead of a string.

The ConnTag field is used when connecting to a z/OS queue manager.

The length of this field is given by MQ_CONN_TAG_LENGTH. This field is ignored if Version is less than MQCNO_VERSION_3.

See ConnTag (MQBYTE128) on Multiplatforms for information on using the connection tag on IBM MQ for Multiplatforms.

Parent topic: Fields for MQCNO