IBM SC34-7012-01 manual The COVR transaction, Messages associated with automatic restart

The COVR transaction

To ensure that CICS reconnects to VTAM in the event of a VTAM abend, CICS keeps retrying the OPEN VTAM ACB using a time-delay mechanism via the non-terminal transaction COVR.

After CICS has completed clean-up following the VTAM failure, it invokes the CICS open VTAM retry (COVR) transaction. The COVR transaction invokes the terminal control open VTAM retry program, DFHZCOVR, which performs an OPEN VTAM retry loop with a 5-second wait. CICS issues a DFHZC0200 message every minute, while the open is unsuccessful, and each attempt is recorded on the CSNE transient data queue. After ten minutes, CICS issues a DFHZC0201 message and terminates the transaction. If CICS shutdown is initiated while the transaction is running, CICS issues a DFHZC0201 message and terminates the transaction.

You cannot run the COVR transaction from a terminal. If you invoke COVR from a terminal, it abends with an AZCU transaction abend.

Messages associated with automatic restart

There are some CICS messages for ARM support, which CICS can issue during startup if problems are encountered when CICS tries to connect to ARM.

The message numbers are:

DFHKE0401	DFHKE0407
DFHKE0402	DFHKE0408
DFHKE0403	DFHKE0410
DFHKE0404	DFHKE0411
DFHKE0405	DFHZC0200
DFHKE0406	DFHZC0201

For the text of these messages, see CICS Messages and Codes.

Automatic restart of CICS data-sharing servers

All three types of CICS data-sharing server—temporary storage, coupling facility data tables, and named counters—support automatic restart using the services of automatic restart manager.

The servers also have the ability to wait during start-up, using an event notification facility (ENF) exit, for the coupling facility structure to become available if the initial connection attempt fails.

Server ARM processing

During initialization, a data-sharing server unconditionally registers with ARM, except when starting up for unload or reload. A server does not start if registration fails, with return code 8 or above.

If a server encounters an unrecoverable problem with the coupling facility connection, consisting either of lost connectivity or a structure failure, it cancels itself using the server command CANCEL RESTART=YES. This terminates the existing connection, closes the server and its old job, and starts a new instance of the server job.

Chapter 7. Automatic restart management 71