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.

You can also restart a server explicitly using either the server command CANCEL RESTART=YES, or the MVS™ command CANCEL jobname,ARMRESTART

By default, the server uses an ARM element type of SYSCICSS, and an ARM element identifier of the form DFHxxnn_poolname where xx is the server type (XQ, CF or NC) and nn is the one- or two-character &SYSCLONE identifier of the MVS image. You can use these parameters to identify the servers for the purpose of overriding automatic restart options in the ARM policy.

Waiting on events during initialization

If a server is unable to connect to its coupling facility structure during server initialization because of an environmental error, such as no coupling facility being available, or loss of connectivity to the structure, the server uses an ENF event exit to wait for cross-system extended services (XES) to indicate that it is worth trying again. The event exit listens for either:

When a relevant event occurs, the server retries the original connection request, and continues to wait and retry until the connection succeeds. A server can be cancelled at this stage using an MVS CANCEL command if necessary.

Server initialization parameters for ARM support

The server startup parameters for ARM support are:

ARMELEMENTNAME=elementname
specifies the automatic restart manager element name, up to 16 characters, to identify the server to ARM for automatic restart purposes.
ARMELEMENTTYPE=elementtype
specifies the automatic restart manager element type, up to 8 characters for use in ARM policies as a means of classifying similar elements.

These parameters are the same for all the data sharing servers. For more details, see CICS System Definition Guide .

Server commands for ARM support

The following are the ARM options you can use on server commands:

CANCEL RESTART={NO|YES}
terminates the server immediately, specifying whether or not automatic restart should be requested. The default is RESTART=NO.

You can also enter RESTART on its own for RESTART=YES, NORESTART for RESTART=NO.

ARMREGISTERED
shows whether ARM registration was successful (YES or NO).
ARM
This keyword, in the category of display keywords that represent combined options, can be used to display all ARM-related parameter values. It can also be coded as ARMSTATUS.

These commands are the same for all the data sharing servers. For more details, see CICS System Definition Guide .

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