The MVS™ logger imposes a limit on the number of data sets per log stream. In practice, this is unlikely to be a problem.
You are strongly recommended to allow the CICS® log manager to manage the size of the system log. If you do so, you do not need to worry about the data set limit being exceeded.
In the unlikely event that you need to retain data beyond the time it would be deleted by CICS, see theCICS Transaction Server for z/OS® Installation Guide for advice on how to define the system log.
If a journal write to a user journal fails because the data set limit is reached, you must delete the tail of the log, or archive it, before you can use the SET JOURNALNAME command to open the journal and make it available for use again. For an example of how to do this, see the CICS Operations and Utilities Guide.