IBM SC34-7012-01 manual Other quiesce interface functions, Non-BWO data set backup start

(4a) SMSVSAM uses the coupling facility to propagate the request to the other SMSVSAM servers in the sysplex.

5.The CICS RLS quiesce exit program schedules a CICS region task (CFQR) to perform asynchronously the required quiesce actions in that CICS region.

6.When CICS has closed all open RLS ACBs for the data set, CICS issues the “quiesce completed” notification (the IDAQUIES macro QUICMP function) direct to SMSVSAM through the control ACB interface.

7.When all CICS regions have replied with the IDAQUIES macro QUICMP function, the SMSVSAM server that handled the original request (from AOR1 in the diagram) sets the quiesced flag in the ICF catalog. This prevents any files being opened in RLS mode for the data set, but allows non-RLS open requests that are initiated, either implicitly or explicitly, by user transactions.

8.SMSVSAM returns to the CICS region that initiated the quiesce request. If the BUSY(WAIT) option was specified on the request, CFQS resumes the waiting application program.

The flow of an unquiesce request is virtually the same as that illustrated in Figure 16 on page 169, with the following differences in operation:

vAs soon as SMSVSAM receives the unquiesce request from the initiating CICS region, it immediately sets the quiesce flag in the ICF catalog to the unquiesce state.

vSMSVSAM invokes the RLS quiesce exit program of each CICS region registered with a control ACB to notify it of the change in the quiesce state.

vThe CICS RLS quiesce exit program returns a “quiesce completed” code to SMSVSAM immediately, and then passes the request to CFQR for processing.

Other quiesce interface functions

In addition to quiesce and unquiesce, there are some other data-set-related functions using the RLS quiesce interface that are not connected with quiescing or unquiescing activity on a data set.

These are functions initiated by DFSMSdss, CICSVR, or VSAM RLS, and may require some processing in those CICS regions that are registered with SMSVSAM. These functions do not cause any change in the ICF catalog quiesced flag.

The other functions provided on the RLS quiesce interface for data-set-related activities are as follows:

Non-BWO data set backup start

A quiesce interface function initiated by DFSMSdss in readiness for non-BWO backup processing for a data set that is open in RLS mode. This function prevents CICS file control issuing RLS update requests against a sphere so that the VSAM sphere can be backed up.

SMSVSAM invokes the CICS RLS quiesce exit program in each region that has an open RLS ACB for the data set.

If any in-flight units of work are using the data set when a QUICOPY notification is received, CICS allows them to complete (or be shunted). CICS then flags its data set name block (DSNB) for the data set to disable further updates. Any unit of work that attempts to update the data set thereafter is abended with an AFCK abend, and SMSVSAM prevents any new file opens for update.

Note: If enabled, the CICS XFCVSDS exit is invoked for this function, with the UEPVSACT parameter set to a value of UENBWST.

170CICS TS for z/OS 4.1: Recovery and Restart Guide