Enabling CICS® TS autojournaling

Parameters specified in the CICS® definitions of VSAM files determine whether or not autojournaling is to be performed, and the types of operations (add, read, or others) that are recorded.

The following parameters must be set in the CICS® file definitions of every VSAM sphere that you want CICS® VR to forward recover from log records produced by CICS® TS autojournaling. See CICS® Resource Definition Guide for a further explanation of the listed parameters.

JOURNAL(number)
Specifies that you want automatic journaling for this file. The journaled data is in the format of the VSAM record. The data to be journaled is identified by the JNLADD, JNLREAD, JNLSYNCREAD, JNLSYNCWRITE, and JNLUPDATE attributes. number is the number that identifies the journal that CICS® is to use for the autojournal. CICS® journal names are of the form DFHJnn, where nn is in the range 1 through 99.
Note:
  1. Automatic journaling is independent of logging to the system and forward recovery logs, as specified by the RECOVERY and FWDRECOVLOG attributes.
  2. When specifying CICS® TS autojournaling for use with CICS® VR, the automatic journaling log stream that is specified must not also be written to by CICS® forward recovery logging.
  3. In releases prior to CICS® Transaction Server for OS/390® Release 1, DFHJ01 was the system log, but that is not now the case.
JNLADD(AFTER)
Specifies that CICS® journals the file control write operation after the VSAM I/O operation on the journal nominated by the JOURNAL attribute.
JNLUPDATE(YES)
Specifies that REWRITE and DELETE operations must be recorded on the journal nominated by the JOURNAL attribute.
JNLSYNCWRITE({YES|NO})
Specifies whether you want the automatic journaling records, which are written for WRITE operations to the journal specified by JOURNAL, to be written synchronously or asynchronously.

During forward recovery processing, CICS® VR applies the log records produced by CICS® TS autojournaling in the order that they are listed on the log. If JNLSYNCWRITE is set to NO, log records might not be written to the log in the correct time sequence. This could cause undesirable results during forward recovery processing. However, setting JNLSYNCWRITE to YES might cause some additional overhead to occur during CICS® TS autojournaling. One of the primary reasons to use CICS® TS autojournaling instead of CICS® forward recovery logging is the possibility of avoiding some overhead, so this benefit can be reduced when JNLSYNCWRITE is set to YES.

Note:
CICS® forward recovery logging is the recommended logging method for use with CICS® VR. However, if you choose to use log records produced by CICS® TS autojournaling for the forward recovery of VSAM spheres, you must not have CICS® forward recovery logging enabled for the same spheres. Enabling both logging methods for forward recovery purposes for the same VSAM sphere, could result in duplicate information being stored in the RCDS, causing unpredictable results during recovery job creation.