z/OS User Exits › z/OS Batch User Exits › TIRBRTRX—Default Retry Limit Exit › Purpose

Purpose

This exit is called at the beginning of a CA Gen Batch application to enable the defined default value for the TRANSACTION RETRY LIMIT system attribute to be modified.

TRANSACTION RETRY LIMIT will be initialized to this value at the beginning of each new execution. This value may subsequently be modified by a SET TRANSACTION RETRY LIMIT statement in an action diagram.

TRANSACTION RETRY LIMIT is used to specify the maximum number of times a transaction is to be retried when one of the following events occurs:

• A RETRY TRANSACTION action diagram statement executes.
• A deadlock or timeout occurs trying to access a database, and no WHEN DATABASE DEADLOCK OR TIMEOUT statement was provided for that entity action statement. (This is not applicable for z/OS transactions running under IMS or IEFAE. An application running under IMS that encounters a deadlock or timeout will be terminated immediately by IMS itself, even if it has a WHEN DATABASE DEADLOCK OR TIMEOUT statement provided.)

In either of these cases, any uncommitted database updates will be rolled back, and an attempt will then be made to execute the application again. Once the number of retries, as indicated by the TRANSACTION RETRY COUNT system attribute, reaches either TRANSACTION RETRY LIMIT or the value specified by the Ultimate Retry Limit Exit, no more retries can occur, and the application will fail with a runtime error if the last retry attempt was unsuccessful.