IPM (Intermittent Performance Monitoring)
Because the CPM mode is normally used for low-frequency, long-duration data collection, you might want to use the IPM mode for short-term, intermittent, high-resolution monitoring of various resources.
By using two Extractors in this way, you can maintain the continuous sampling function while also obtaining the additional sampling data you need for another purpose. IPM is generally used to sample head movement, individual devices, and the like.
When you detect a trend that could be impacting performance, or when you have identified a distinct performance problem, you can use the IPM mode to run a set of samplers at high frequency rates. By concentrating your sampling of specific system resources at high intervals, the IPM data provides focused information about current performance problems for these resources. You can use the information from IPM mode sampling to determine specific causes of system performance difficulties.
BMC Software recommends that you run this mode only when necessary to minimize system impact. Initiating IPM mode to investigate specific areas of activity or to monitor specific devices during peak periods of activity should be at the discretion of your system programmer.
Because IPM mode (with more frequent sampling rates) has a higher overhead associated with it and provides concentrated sampling, the default Started Task JCL shipped with the Extractor does not initialize IPM mode at startup.
To start the IPM mode Extractor, you can either use the MODIFY command (for more information, see Using-the-MODIFY-command-to-change-Extractor-operation), or change the default setting on the MVS PAS PROC to DC=IPM (for more information, see Defining-Extractor-control-statements).
Two Extractor control statements are invalid in this mode: CSMON and EXTSUM.
A sample control statement for invoking the IPM monitor is shown in CMFIPM00-control-statement-set.