IBM SC34-7012-01 manual RLS quiesce and unquiesce functions

The RLS quiesce and unquiesce functions

The RLS quiesce and unquiesce functions are initiated by a CICS command in one region, and propagated by the VSAM RLS quiesce interface to other CICS regions in the sysplex.

When these functions are complete, the ICF catalog shows the quiesce state of the target data set. The state of the quiesce flag in the ICF catalog controls whether a data set can be opened in RLS mode:

vWhen a quiesce operation has been completed throughout the sysplex, SMSVSAM sets the quiesced flag to prevent applications (either CICS or batch) from opening the data set in RLS mode.

You can open a quiesced data set in non-RLS mode only.

vWhen an unquiesce operation has been completed, SMSVSAM clears the quiesced flag to permit the data set to be opened in RLS mode.

You can open an unquiesced data set in either RLS or non-RLS mode, the mode for the entire sysplex being determined by the first ACB opened.

Normally, a data set cannot be opened for update in non-RLS access mode if SMSVSAM is holding retained locks against the data set. Thus, to enable a non-RLS batch program to update a recoverable data set that CICS regions have open in RLS mode, take the following steps:

1.Resolve shunted units of work that are holding retained locks

2.Quiesce the data set

3.Run the batch update job

4.Unquiesce the data set

CICS transactions that try to access a quiesced data in RLS-mode fail with a NOTOPEN condition. Non-RLS accesses are permitted subject to the data set’s

VSAM SHAREOPTIONS.

For more information, see “Switching from RLS to non-RLS access mode” on page 172.

Illustration of the quiesce flow across two CICS regions

Figure 16 on page 169 illustrates the operation of the CICS RLS quiesce operation. The notes that follow explain the numbered points.

168CICS TS for z/OS 4.1: Recovery and Restart Guide