Performance and Diagnostic Advisor configuration settings

Specify settings for the Performance and Diagnostic Advisor.

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        Servers > Server Types > WebSphere application servers > server > Performance and Diagnostic Advisor Configuration under the Performance section.

Enable Performance and Diagnostic Advisor Framework

Specifies whether the Performance and Diagnostic Advisor runs on the server startup.

The Performance and Diagnostic Advisor requires that the Performance Monitoring Infrastructure (PMI) be enabled. It does not require that individual counters be enabled. When a counter needed by the Performance and Diagnostic Advisor or is not enabled, the Performance and Diagnostic Advisor enables it automatically. When disabling the Performance and Diagnostic Advisor, we might want to disable Performance Monitoring Infrastructure (PMI) or the counters that Performance and Diagnostic Advisor enabled. The following counters might be enabled by the Performance and Diagnostic Advisor:

• ThreadPools (module)
  • Web Container (module)
    • Pool Size
    • Active Threads

  • Object Request Broker (module)
    • Pool Size
    • Active Threads

• JDBC Connection Pools (module)
  • Pool Size
  • Percent used
  • Prepared Statement Discards

• Servlet Session Manager (module)
  • External Read Size
  • External Write Size
  • External Read Time
  • External Write Time
  • No Room For New Session

• System Data (module)
  • CPU Utilization
  • Free Memory

Enable automatic heap dump collection

Specifies whether the Performance and Diagnostic Advisor automatically generates heap dumps for post analysis when suspicious memory activity is detected.

Calculation Interval

Length of time over which data is taken for this advice.

PMI data is taken over an interval of time and averaged to provide advice. The calculation interval specifies the length of time over which data is taken for this advice. Details within the advice messages display as averages over this interval. The default is automatically set to four minutes.

Maximum warning sequence

The maximum warning sequence refers to the number of consecutive warnings that are issued before the threshold is relaxed.

For example, if the maximum warning sequence is set to 3, the advisor only sends three warnings to indicate that the prepared statement cache is overflowing. After three warnings, a new alert is only issued if the rate of discards exceeds the new threshold setting. The default is automatically set to one.

Number of processors

Number of processors on the server.

This setting is helpful to ensure accurate advice for the specific configuration of the system. Depending the configuration and system, there may be only one processor utilized. The default is automatically set to two.

Minimum CPU For Working System

The minimum CPU for working system refers to the point at which concurrency rules do not attempt to free resources in thread pools.

There is a set of concurrency alerts to warn you if all threads in a pool are busy. This can affect performance, and it may be necessary for you to increase them. The CPU bounds are a mechanism to help determine when an application server is active and tunable.

The Minimum CPU for working system sets a lower limit as to when we should consider adjusting thread pools. For example, say we set this value to 50%. If the CPU is less than 50%, concurrency rules do not try to free up resources by decreasing pools to get rid of unused threads. That is, if the pool size is 50-100 and only 20 threads are consistently used then concurrency rules would like to decrease the minimum pool size to 20.

CPU Saturated

The CPU Saturated setting determines when the CPU is deemed to be saturated.

There is a set of concurrency alerts to warn you if all threads in a pool are busy. This can affect performance, and it may be necessary for you to increase them. The CPU bounds are a mechanism to help determine when an application server is active and tunable.

The CPU saturated setting determines when the CPU has reached its saturation point. For example, if this is set to 95%, when the CPU is greater than 95% the concurrency rules do not try to improve things, that is, increase the size of a thread pool.

Use the Performance and Diagnostic Advisor

Obtain advice from the advisors