The AKPFREQ parameter specifies the number of write requests to the CICS® system log stream output buffer required before CICS writes an activity keypoint.
- AKPFREQ={4000|number}
-
- 4000
- This is the default. You are recommended to allow AKPFREQ to assume its default value.
- number
number can be 0 (zero) or any
value in the range 50 through 65535. You cannot specify a number in
the range 1 - 49. 
If you specify AKPFREQ=0, no activity keypoints are written, with the following consequences:- The CICS system log automatic deletion mechanism does not work so efficiently in this situation. The average system log occupancy would merely increase, maybe dramatically for some users. Without efficient automatic deletion, the log stream spills on to secondary storage, and from there onto tertiary storage (unless you control the size of the log stream yourself).
- Emergency restarts are not prevented, but the absence of activity keypoints on the system log affects the performance of emergency restarts because CICS must read backwards through the entire log stream.
- Backout-while-open (BWO) support is seriously affected, because without activity keypointing, tie-up records are not written to the forward recovery logs and the data set recovery point is not updated. Therefore, for forward recovery to take place, all forward recovery logs must be kept since the data set was first opened for update after the last image copy. For more information about the effect of AKPFREQ=0 on BWO, see Effect of disabling activity keypointing.
- Replication support is affected,
because without activity keypointing, tie-up records are not written
to replication logs. This can affect the performance of the replication
engine.
For more information about activity keypointing, see Setting the activity keypoint frequency.
