How can one use CA Mainframe Application Tuner to measure IMS MPRs (Message Processing Regions)?
Mainframe Application Tuner (MAT) measures jobsteps, or TCBs within address spaces. When you define a measurement for IMS, in the definition you tell MAT what MPR you want to measure. MAT will collect data on whatever transaction or transactions that run in the MPR during that measurement. MAT doesn't support IMSPLEX and MAT's IMS support doesn't have the capability for you to define a transactional level measurement where MAT goes to go find the MPR or MPRs it is running in and collect statistics.
MAT does have enhancement requests to support IMSPLEX and add the ability for you to tell MAT what transaction you want and then chase it to all the MPRs, but that is in the future.
There are three options.
One is that you target the problem transaction to a single MPR and measure that MPR.
Two is you implement PMAs IMS subsystems functionality. With PMA you schedule measurements against a number of MPRs throughout the day and then define the MPRs to a 'logical' IMS subsystem within PMA. PMA will extract the data from MAT list files into PMA's IMS data repository where PMA will group all the data together into this IMS 'logical' subsystem and give you a single view of each transaction that was captured from all of the measurements.
The third option is also PMA related and depends on whether you run Sysview or Mainview. If you run either of those PMA has a function that allows the extraction of IMS transaction data from log records created by Sysview or Mainview.