Environment-dependent WebSphere MQ for z/OS functions

 

The main differences to be considered between WebSphere MQ functions in the environments in which WebSphere MQ for z/OS runs are:

• WebSphere MQ for z/OS supplies the following trigger monitors:

  • CKTI for use in the CICS environment

  • CSQQTRMN for use in the IMS™ environment

  You must write your own module to start applications in other environments.

• Syncpointing using two-phase commit is supported in the CICS and IMS environments. It is also supported in the z/OS batch environment using transaction management and recoverable resource manager services (RRS). Single-phase commit is supported in the z/OS environment by WebSphere MQ itself.

• For the batch and IMS environments, the MQI provides calls to connect programs to, and to disconnect them from, a queue manager. Programs can connect to more than one queue manager.

• A CICS system can connect to only one queue manager. This can be made to happen when CICS is initiated if the subsystem name is defined in the CICS system startup job. The MQI connect and disconnect calls are tolerated, but have no effect, in the CICS environment.

• The API-crossing exit allows a program to intervene in the processing of all MQI calls. This exit is available in the CICS environment only.

• In CICS on multiprocessor systems, some performance advantage is gained because MQI calls can be executed under multiple z/OS TCBs. For more information, see the WebSphere MQ for z/OS Concepts and Planning Guide.

These features are summarized in Table 1.

z/OS environmental features

	CICS	IMS	Batch/TSO
Trigger monitor supplied	Yes	Yes	No
Two-phase commit	Yes	Yes	Yes
Single-phase commit	Yes	No	Yes
Connect/disconnect MQI calls	Tolerated	Yes	Yes
API-crossing exit	Yes	No	No
Two-phase commit is supported in the Batch/TSO environment using RRS.

 

Parent topic:

Using and writing applications on WebSphere MQ for z/OS

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