RRS and distributed syncpoint/protected conversations
Regardless of whether the SYNCLVL setting is NONE, CONFIRM, or SYNCPOINT, if RRS=Y, z/OS® Resource Recovery Services is the sync point manager and coordinates the update and recovery of multiple protected resources. RRS controls how and when protected resources are committed by coordinating with the resource managers, such as IMS, that have registered with RRS.
RRS supports the Common Programming Interface for Resource Recovery (CPI-RR), an element of the SAA CPI that specifies resource recovery and coordinates recovering local and distributed resources.
Definitions:
- A protected resource is a set of local or distributed data that is updated in a synchronized and controlled manner. In the APPC environment, a protected resource is a resource that is updated in an allocated conversation in which SYNCLVL=SYNCPT has been specified.
- A resource manager is a product, such as IMS, that owns protected data resources that are updated in an APPC conversational environment in which SYNCLVL=SYNCPT has been specified. IMS acts as a resource manager for DL/I data, Fast Path data, and the message queues.
The three participants in resource recovery include:
- RRS (sync point manager)
- Resource manager (such as IMS or Db2 for z/OS)
- Application program
The following figure shows the three participants in the resource recovery process, and their interaction.
