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Chapter 11. Defining system and general log streams
All CICS system logging and journaling is controlled by the CICS log manager,
which uses MVS system logger log streams to store its output.
About this task
CICS logging and journaling can be divided into four broad types of activity:
System logging
CICS maintains a system log to support transaction backout for recoverable
resources. CICS implements system logging automatically, but you can
define the log stream as DUMMY to inhibit this function. However, if you
specify TYPE(DUMMY) for the system log, you are running without any
transaction backout facilities and without any restart capability, and you
can start CICS with START=INITIAL only.
CICS also supports programming interfaces that enable you to write your
own data to the system log, but user-written records should be for
recovery purposes only.
See “Defining system log streams” on page 108.
Forward recovery logging
CICS supports forward recovery logs for VSAM data sets.
Forward recovery logging is not automatic—you must specify that you
want this facility for your files, and also define the forward recovery log
streams.
See “Defining forward recovery log streams” on page 116.
Autojournaling
CICS supports autojournaling of file control data and terminal control
messages. Autojournaling is generally used for audit trails.
Autojournaling is not automatic—you must specify that you want this
facility for your files and terminal messages, and also define the general
log streams to be used.
See the JOURNAL attribute described in FILE and PROFILE resource
definition attributes in the CICS Resource Definition Guide for information
about specifying automatic journaling on FILE and PROFILE resource
definitions.
User journaling
CICS supports programming interfaces to enable CICS applications to
write user-defined records to user journals, which are held on general log
streams.
See the CICS System Definition Guide for information about defining general
log streams for user journals.
Autojournaling and user journals play no part in CICS recovery and therefore are
not discussed here.
The CICS log manager writes the data associated with these logging and
journaling activities to two types of MVS log stream:
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