RRS batch adapter
The transaction management and recoverable resource manager services (RRS)
adapter:
- Uses z/OS RRS for commit control.
- Supports simultaneous connections to multiple WebSphere MQ subsystems running
on a single z/OS instance from a single task.
- Provides z/OS-wide coordinated commitment control (using z/OS RRS) for
recoverable resources accessed through z/OS RRS compliant recoverable managers
for:
- Applications that connect to WebSphere MQ using the RRS batch adapter.
- DB2-stored procedures executing in a DB2-stored procedures address
space that is managed by a workload manager (WLM) on z/OS.
- Supports the ability to switch a WebSphere MQ batch thread between TCBs.
WebSphere MQ for z/OS provides two RRS batch adapters:
- CSQBRSTB
- This adapter requires you to change any MQCMIT and MQBACK statements
in your WebSphere MQ application to SRRCMIT and SRRBACK respectively. (If
you code MQCMIT or MQBACK in an application linked with CSQBRSTB, you receive
MQRC_ENVIRONMENT_ERROR.)
- CSQBRRSI
- This adapter allows your WebSphere MQ application to use either MQCMIT and
MQBACK or SRRCMIT and SRRBACK.
Note:
CSQBRSTB and CSQBRRSI are shipped with linkage attributes
AMODE(31) RMODE(ANY). If your application loads either stub below the 16 MB
line, first relink the stub with RMODE(24).
Migration
You can migrate existing Batch/TSO WebSphere MQ applications to exploit RRS coordination
with few or no changes. If you link-edit your WebSphere MQ application with the CSQBRRSI
adapter, MQCMIT and MQBACK syncpoint your unit of work across WebSphere MQ and all
other RRS-enabled resource managers. If you link-edit your WebSphere MQ application
with the CSQBRSTB adapter, change MQCMIT and MQBACK to SRRCMIT and SRRBACK
respectively. The latter approach is preferable; it clearly indicates that
the syncpoint is not restricted to WebSphere MQ resources only.