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Interests and Roles

Transaction Interests

For a resource manager to participate in a transaction, it must register an interest in that transaction. The existence of an interest informs the transaction manager that the resource manager's exits should be invoked during commit and backout processing for the transaction.

Roles

When an interest is registered, the role that the resource manager is to play with respect to the transaction is specified. CA IDMS recognizes the following roles:

When a central version application calls a resource manager interface to access a remote resource, the interface registers a CRM interest in the application's current transaction, since it is acting as a remote participant in that transaction. An SDSRM interest is registered before or during the prepare stage of transaction processing to record a remote transaction manager as the coordinator for a transaction.

As a two-phase commit operation proceeds, interests are assigned states similar to those outlined in 20.2.7, "Transaction States". For example, if an interest's prepare exit returns OK, then the state of the interest is set to InDoubt, reflecting the fact that the associated resource manager is waiting for the final commit or backout directive.