At intervals, CICS® itself checks for the availability of the MVS™ logger. It uses
one of two procedures to perform these checks, depending on your operating
system.
- If you are using OS/390® Release 2.10 or z/OS® Release 1.1, and the MVS logger PTF UW79565
has been applied, CICS checks
by querying the system log connection status. This is the more efficient of
the two procedures.
- If your operating system does not meet these conditions, CICS checks by
initiating a BROWSE START operation on the system log.
If the check fails, CICS either abends or quiesces, depending on the
returned MVS logger reason code.
The interval at which CICS checks for the availability of the MVS logger
varies, depending on the amount of system logging activity in the CICS region.
The first check is made after CICS has not made contact with the MVS logger
for 10 seconds. If CICS continues to perform no system logging after the first
check, the interval between checks doubles each time, up to a maximum of 600
seconds. If CICS makes contact with the MVS logger at any point, the interval
between checks is halved, down to a minimum of 10 seconds.
The checking interval can be affected by the exit time interval specified
in the ICV system initialization parameter, as follows:
- If the value specified in the ICV system initialization parameter is less
than 10 seconds, it has no effect on the checking interval.
- If the value specified in the ICV system initialization parameter is greater
than 10 seconds but less than 600 seconds, the checking interval varies between
the value specified in the ICV system initialization parameter, and 600 seconds.
The first check is made after an interval corresponding to the value in the
ICV system initialization parameter, instead of being made after 10 seconds.
The minimum checking interval is the value in the ICV system initialization
parameter.
- If the value specified in the ICV system initialization parameter is greater
than 600 seconds, the checking interval does not vary, and always corresponds
to the value in the ICV system initialization parameter.
The statistics field IGXQUERY in the CICS log manager statistics enables
you to monitor the number of checks that CICS makes for the availability of
the MVS logger.
Tuning the region exit interval (ICV)
Interpreting journalname and log stream statistics
Monitoring the logger environment
ICV
[[ Contents Previous Page | Next Page Index ]]