ConnTag (MQBYTE128) on Multiplatforms

A connection tag is conceptually similar to a connection identifier, but might span multiple related connections, identifying them as a single application instance. On Multiplatforms, the connection tag is generated by the queue manager at connection time.

[V9.1.3 Jul 2019] For more information, see connection identifier and application instance.

Generated connection tags are semi human readable. That is, they can be displayed and filtered in MQSC as if strings in the local character set. Connections that are known by IBM MQ to be related are automatically assigned the same connection tag. This assignment is particularly important to application balancing.

The generated connection tag is visible in three ways:

In the output MQCNO structure on an MQCONNX call, when MQCNO_GENERATE_CONN_TAG is specified.
In the output from DISPLAY CONN (or programmatic equivalents).
In the output from DISPLAY APSTATUS (or equivalents).

The tag ceases to be valid when the application terminates or issues the MQDISC call.