Reading journal records offline
Access to journaled data in log streams is provided through an MVS subsystem
interface (SSI), LOGR. Yourexisting user programs can read the general log
streams, providing you specify, in your batch job JCL, the SUBSYS parameter and
supporting options on the DD for log streams. By specifying the LOGR subsystem
name on the SUBSYS parameter, you enable LOGR to intercept data set open and
read requests at the SSI, and convert them into log stream accesses.
Depending on the options specified on the SUBSYS parameter, general log stream
journal records are presented either:
vIn the record format used at CICS/ESA 4.1 and earlier, for compatibility with
older utilities (selected by the COMPAT41option), or
vIn the CICS Transaction Server for OS/390 format (introduced at CICS
Transaction Server for OS/390 Release 1), for newer or upgraded utilities
needing to access log record information.
CICS system log records are only available in the CICS Transaction Server for
OS/390 format, so you must ensure that any utilities that handled system log
records in releases prior to CICS Transaction Server for OS/390 Release 1 are
converted to handle this format.
Journal records can be read offline by user-written programs. Youcan generate the
DSECTsthat such programs need by including certain statements in the program
code, as follows:
vFor records in the CICS Transaction Server for OS/390 format on general logs,
offline user-written programs can map journal records by including an INCLUDE
DFHLGGFD statement. This generates the assembler version of the DSECT.
vFor records formatted with the COMPAT41option, offline user-written programs
can map journal records by issuing the DFHJCR CICSYST=YES statement,
which results in the DFHJCRDS DSECT being included in the program.
The DSECT thus generated is identical to that obtained for CICS programs by
the COPY DFHJCRDS statement, except that the fields are not preceded by a
CICS storage accounting area. The DSECT is intended to map journal records
directly in the block, rather than in a CICS storage area.
The following section describes the structure of CICS Transaction Server for
OS/390-formatted journal records. The structure and content of CICS/ESA
4.1-format journal records are described in “Structure and content of
COMPAT41-formatjournal records” on page 645.
Structure and content of CICS Transaction Server for OS/390 formatjournal records
SMF records
The following description does not apply to journal records written to an SMF
data set. These are described on page 653.
General logs (that is, those containing forward-recovery logs, auto-journals, and
user journals) can be presented in the format introduced at CICS Transaction
journaling
632 CICS TS for OS/390: CICS Customization Guide