Managing IMS performance

Managing IMS performance requires you to balance workloads and resources, and monitor the effects of your load balancing decisions. You monitor IMS to determine whether IMS transactions are processing at an acceptable rate.

Even though IMS is a complex environment, something as simple as a stopped database can delay the completion of the IMS transactions. Typically, users might observe the effects of resource contention or unavailable resources and inform help desk personnel.

Managing your system is an iterative process that comprises the following steps:
  1. Monitoring the performance of your system.
  2. Identifying the root cause when a workload or key system resource shows a problem.
  3. Correcting problems that arise.
  4. Using the data from your observations and your knowledge of data center priorities to determine performance targets.
  5. Continually monitoring your system.

Monitor performance

Although your site might not have formal, written performance objectives, almost all sites have informal objectives. OMEGAMON® for IMS can help you translate informal objectives into formal objectives, and can also help you monitor your system performance. After OMEGAMON for IMS is up and running, you can start monitoring current IMS performance by asking yourself the following questions:
  • How well are the groups of transactions performing?
  • How well are the IMS resources performing?
  • Are the problems that OMEGAMON for IMS identifies really problems for the site?
  • Is OMEGAMON for IMS missing any problems for the site?

See the IBM® Tivoli® OMEGAMON for IMS on z/OS®: Response Time Analysis Reference for more information about how to set response-time exception values.

Identify and correct problems

When one of the status indicators signals that a problem exists, OMEGAMON for IMS can help you identify the cause of this problem.

For example, OMEGAMON for IMS provides information about what might be causing poor performance for a group of transactions. It helps you identify which resources or system components are busiest or unusually active when the response time for a particular group of transactions is delayed. You can then use this information to correct the problem. If you must issue an IMS command to correct the problem, you can go to panels where you select IMS commands from a menu, or you can enter IMS commands directly.

The OMEGAMON for IMS online help system also provides advice for resolving problems.