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(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:
v As 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.
v SMSVSAM 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.
v The 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.
170 CICS TS for z/OS 4.1: Recovery and Restart Guide