Performance considerations for impact analysis

To get the best performance possible for impact analysis calculations, review the configuration options and configure system properties and rules to maximize performance for your environment.

Although performance is not the only consideration when determining how to configure impact analysis, it is an important factor. Consider the following recommendations when configuring impact analysis:
  1. Make the pmcom.TraversalMaxThreads system property large enough to take advantage of available resources.

    The IBM Control Desk impact analysis engine uses a multi-threaded design and can analyze several different CI relationships at the same time. The pmcom.TraversalMaxThreads system property specifies the maximum number of threads to process at one time.

    Set the TraversalMaxThreads property value based on your physical system resources; that is, based on the amount of memory and CPU core that are available on the machine where Control Desk is running. If the value is set too low, then performance suffers. If the value is too high, then you can get “out of memory” errors. A good estimate for this property is 10 times the number of CPU cores in the system. As a best practice, run a few tests with different values to find the largest value that shows improvement. At some point, as you increase this setting, there will no longer be any increase in performance. When testing, remember the threads are also shared with other applications that use the multi-threading features, including CI promotion and the CI topology viewer.

  2. Mark a minimum number of CI classifications as Show in Impact Analysis Results.

    When creating classifications for CIs, selecting the Show in Impact Analysis Results check box specifies that the classification is included in impact analysis results. If this field is selected, any CIs with this classification are included in the impact analysis results. As the number of CIs reported in the impact analysis results increases, the time to complete the execution increases. As a best practice, restrict the number of classifications that have this value to classifications with high business value, for example, business applications or business services.

  3. Set the pmchgiarule.maxdepth system property to the minimum depth that returns all the impacts of interest.

    This system property specifies the number of levels of related CIs the engine examines to calculate impacts. The default maximum depth is 10.

  4. Minimize the use of conditions in impact analysis rules because evaluation of a large number of conditions can adversely affect performance.
Parent topic: Configuring impact analysis rules

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