API exits on clients

A client uses the PreConnect exit to modify the behavior of the MQCONN and MQCONNX calls and does not support API exit properties.

PreConnect exit

On a client, the PreConnect exit can be used to look up the channel definition from a central repository, such as an LDAP server.

The PreConnect exit can also modify any parameter, or all the parameters, on an MQCONN or MQCONNX call itself, for example, the queue manager name.

In the case of client applications, the PreConnect exit must be called before the API exit because the MQCONN or MQCONNX API exit is called only once the name of the queue manager is known and this name can be changed by the PreConnect exit.

Note that only the initial MQCONN or MQCONNX call invokes the exit.

API exit properties

On a server, API exits can register an MQXEPO structure at initialization time. The MQXEPO structure contains the ExitProperties field which details the group of properties the exit is interested in. This has the effect of generating a separate message property handle which the exit can manipulate separately from any application message property handle.

On a client, API exit properties are not supported. If an attempt is made to register a property group name on a client, the function fails with a reason code of MQRC_EXIT_PROPS_NOT_SUPPORTED.