Vsam files accessed in non-rls mode – IBM SC34-7012-01 User Manual

Page 139

Advertising
background image

uses the ICF catalog entry recovery attributes instead of the FILE resource. To
force CICS to use the FILE resource attributes instead of the catalog, set the
NONRLSRECOV

system initialization parameter to FILEDEF.

v

You define the recovery attributes for BDAM files in file entries in the file
control table (FCT).

VSAM files accessed in non-RLS mode

You can specify support for both forward and backward recovery for VSAM files
using the RECOVERY and FWDRECOVLOG options. You define the type of data
set backup you want using the BACKUPTYPE parameter.

RECOVERY(ALL)

If you specify RECOVERY(ALL), CICS provides both forward and backout
recovery for the file. Using the services of the CICS recovery manager and log
manager, CICS file control writes:

v

Before-images of updated records to the system log stream. These are used
to back out file changes following a transaction abend or during an
emergency restart after a CICS abnormal termination.

v

After-images to the general log stream referenced by the FWDRECOVLOG
option. The after-images comprise the following:
– A write_add_complete record when a new record is added
– A write_delete record when a record is deleted
– A write_update record when a record is updated
File control also writes the following to the forward recovery log:
– FILE_OPEN tie-up records
– FILE_CLOSE tie-up records
– TAKE_KEYPOINT tie-up records
– Data set BACKUP tie-up records

See the CICS Customization Guide for details of all these forward recovery
records.

CICS forward recovery support is totally independent of automatic journaling.
However, autojournal records, which are controlled by the JOURNAL and
associated JNLxxx options on the file resource definition, can be written to the
same general log stream as forward recovery data. To do this, specify on the
JOURNAL option a journal identifier that maps to the same forward recovery
log stream. See the CICS System Definition Guide for information about
mapping CICS journal identifiers to log streams through journal model
resource definitions.

Note:

The use of autojournal records for forward recovery purposes is not

recommended for VSAM files.

RECOVERY(BACKOUTONLY)

If you specify RECOVERY(BACKOUTONLY), CICS provides backout recovery
only, writing only before-images to the system log.

BACKUPTYPE(DYNAMIC)

If you specify BACKUPTYPE(DYNAMIC), CICS supports the DFSMS
backup-while-open (BWO) facility, enabling the data set to be backed up while
open. If you specify STATIC, all CICS files open against a data set must be
closed before it can be backed up. For information about the
backup-while-open (BWO) facility, see Chapter 18, “Backup-while-open
(BWO),” on page 203.

Chapter 12. Defining recoverability for CICS-managed resources

127

|
|
|

Advertising