By BTS-set we mean the set of CICS® regions across which related BTS processes and activities may execute. All the regions in a BTS-set:
There are two methods of sharing the repository data set:
Within an MVS sysplex, it is possible to have multiple BTS-sets--see Figure 53. Imagine, for example, that within your sysplex you operate two CICSplexes. You could decide to divide your BTS processes by process-type, between the two CICSplexes. Alternatively, you could decide to set up two BTS-sets within the same CICSplex.
Using separate BTS-sets is a high-level form of workload separation. By definition, routing of activities between BTS-sets is not possible.
When you create a BTS-set, the activities that constitute a single process may execute on several regions. Therefore, in order to collate the audit data for each process, your audit logs should use MVS shared logstreams.
If all the CICS regions in your BTS-set are in the same MVS image, you can define the logstreams to use either coupling facility structures or DASD-only logging. However, if the CICS regions are on different MVS images, the logstreams should use coupling facility structures rather than DASD-only logging. This is because CICS regions on different MVS images cannot access the same DASD-only logstream at the same time.
If your BTS-set spans multiple MVS images and you use DASD-only logstreams for your BTS logs, you will not be able to use shared logstreams. In this case, the audit records for a particular process could be split between several logstreams; you have to collate the data yourself.
For further information about audit logs, see Creating a BTS audit trail.