Collecting and interpreting IMS monitoring data

Monitoring is the collection and interpretation of IMS data. This data helps you understand the daily needs of the system and provides an insight into areas that might need changes.

Monitoring should be an ongoing task because:

• Monitoring helps you establish base profiles, workload statistics, and data for capacity planning and prediction.
• Monitoring gives early warning and comparative data to help you prevent performance problems.
• Monitoring validates tuning you have done in response to a performance problem and ascertains the effectiveness of that tuning.

For multi-system networks, plan to obtain both statistical and performance data for IMS online systems that are part of the network. You can use the same monitoring tools that are used for generating performance data for single IMS systems:

• The IMS Monitor can be executed concurrently in several systems. You obtain IMS Monitor reports for each individual IMS system and coordinate your processing analysis.
  Tip: The IMS Monitor user exit provides a framework and exit point for access to the IMS Monitor data in real-time.
• For DB/DC and DCCTL systems:
  • The IMS Statistical Analysis utility (DFSISTS0) produces summaries of transaction traffic for each individual system. Again, you combine the statistics for a composite picture.
  • The IMS Log Transaction Analysis utility (DFSILTA0) enables you to trace transactions across multiple systems and examine the traffic using the various active physical links.

You can use IBM® z/OS® Workload Interaction Correlator to gather workload data for IMS systems and other participating z/OS components and middleware to diagnose performance issues across the stack. IBM z/OS Workload Interaction Correlator generates synchronized, standardized, and summarized data every 5 seconds across the z/OS stack, including IMS, by grouping similar jobs together in a common software context.

Overall, conclusions from continuous monitoring and historical records provide a good starting place from which to answer end-user complaints and to provide initial directions for tuning projects.