Address Space models supported by WebSphere MQ for HP-UX on IA64 (IPF)

 

HP-UX supports two Address Space models:

• MGAS - Mostly Global Address space (this is the default and is used by WebSphere MQ)

• MPAS - Mostly Private Address space

The MPAS model is new on the HP-UX IA64 platform.

For many types of application the Address Space model used has little apparent effect, however there are implications for applications which use System V Shared Memory. In particular, applications using the MPAS model cannot attach System V Shared Memory created by an application which is configured to use the MGAS model when the shared memory is marked as being available to 32-bit applications.

WebSphere MQ is built using the MGAS Address Space model which means that :

• Applications built using the MGAS model can connect to WebSphere MQ.

• Applications built using the MPAS model cannot connect to WebSphere MQ if they connect using the server libraries (libmqm and similar).

• Applications built using the MPAS model can connect to WebSphere MQ if they connect using the client libraries (libmqic and similar), however facilities such as WebSphere MQ trace are, by default, not available.

If you have an application that is built as MPAS we can change it to use the MGAS model using the following command:

chatr +as default program-name

If you have a requirement to use MPAS applications with WebSphere MQ, you can configure WebSphere MQ to allow both MGAS and MPAS applications to connect by setting the variable AMQ_64BIT_SUBPOOL_ONLY; issue the command

export AMQ_64BIT_SUBPOOL_ONLY=1 

in the environment before starting the queue manager. This allows MPAS applications to connect to the queue manager but it prevents 32-bit applications connecting to the queue manager using the server libraries.

By default COBOL applications built using Micro Focus Server Express are built using the MPAS model. In order to use Micro Focus COBOL applications and WebSphere MQ on the IA64 (IPF) platform change the addressing model of your compiled COBOL applications to MGAS or set the AMQ_64BIT_SUBPOOL_ONLY environment variable as described above. More details on the MGAS and MPAS address space models can be found in the HP-UX documentation.

 

Parent topic:

Building your application on HP-UX

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