CICS® VR VSAM batch logging, referred to as batch
logging, provides logging of updates made to VSAM data sets by batch
jobs. Two types of batch logging are available, forward recovery
logging and undo logging.
Forward recovery logging writes an after-image log record
to a forward recovery log stream for every update made to the VSAM
data set by a batch job. Therefore, if the data set becomes corrupted, CICS VR
forward recovery can be used to recreate the updates made by the batch
job.
Undo logging writes a before-image log record to an
undo log stream for every update made to the VSAM data set by a batch
job. Therefore, if the batch job encounters an abend, CICS VR
batch backout can be used to remove the updates made by the failed
batch job or batch job step.
Forward recovery logging, undo logging, or both can
be enabled for a VSAM data set. This section explains the tasks required
to enable batch logging for your VSAM data sets.
CICS VR VSAM batch logging requires the following:
z/OS 1.12 or higher, with all necessary PTFs applied.
Refer to Operating environment for details. 
- Activation of the CICS VR server address space.
For more information, see Activating the CICS VR server address space.
- All VSAM data sets that request batch logging must be SMS-managed.
- The LOGR Couple Data Set (LOGR policy) must be defined. The LOGR
policy includes the following definitions:
- Log stream definitions
- Coupling facility list structure definitions, if applicable
- Data containing the current state of a log stream, for example;
whether a log stream is currently connected to the coupling facility
structure.
For more information on the formatting a LOGR couple data set
and defining the LOGR policy, see z/OS MVS Setting
Up a Sysplex, section "Preparing to Use System Logger Applications".
CICS VR VSAM batch logging calls the MVS™ system
logger to write the log records to the MVS log
stream. The MVS system logger is a component of z/OS®,
which provides a programming interface to access records on a log
stream. For more information about the MVS system
logger, see the following publications:
- z/OS MVS Programming: Assembler Services
Guide
- z/OS MVS Programming: Assembler Services
Reference ABE-HSP
- z/OS MVS Setting Up a Sysplex
The following topics are described in this section:
- Using CICS VR VSAM batch logging
- Enabling CICS VR VSAM batch logging
- Setting up the logging environment for CICS VR
VSAM batch logging
- Detecting batch logging error conditions