Method Statistics

  The method statistics view shows information on the distribution of calls to the same method.

Recording method statistics is a memory intensive operation, so it is split from regular CPU recording. To record method statistics, click  Record method statistics in the tool bar or select View->Record Method Statistics from JProfiler's main menu. If you have previously recorded method statistics, the old recorded data will be lost. Bookmarks will be added when recording is started or stopped manually.

If CPU recording is not enabled, it will be enabled when you start recording method statistics. Note that CPU recording will not be stopped when you stop recording method statistics.

  The method statistics view shows a table with all methods from profiled classes that were invoked during method statistics recording. The following columns are shown in the table:
  • Method
    The name of the method and its parameters.
  • Total Time
    The total time spent in the method.
  • Invocations
    The number of times a method was called.
  • Average Time
    The average time spent in a method. This is equal to the total time divided by the invocation count.
  • Median Time
    The median time is the time for which half of the method calls were shorter and half were longer.
  • Minimum Time
    The minimum time of a single method invocation.
  • Maximum Time
    The maximum time of a single method invocation.
  • Standard Deviation
    The standard deviation measures the breadth of the distribution of method call times. If all method call times are nearly equal, the value will be close to zero, the more spread-out the call times are, the higher the standard deviation will be.
  • Outlier Coefficient
    The outlier Coefficient is calculated as (maximum time - median time) / median time. It measures how significant the maximum time deviates from the median time. Outliers with small times are not considered. Methods with high outlier coefficients are suitable candidates for exceptional method run measurements in the call tree view.

You can sort the table on all columns. Double-clicking on a table row will show the source code of the selected method.

  You can use this view as a starting point for determining which methods are candidates for exceptional method run recording. Once you have identified methods with a high outlier coefficient, you can right-click them in the table and choose  Add As Exceptional Method from the context menu.
  Below the method table, a graph with the distribution of invocation counts versus call times is shown. The graph is always shown for the currently selected method in the method table.

By default, the graph shows invocation counts on a linear scale. However, in order to identify outliers with a low relative frequency, it is useful to switch to a logarithmic axis. This can be done in the view settings or in the context menu.

The graph can be exported to HTML or CSV by right-clicking into the graph area and selecting Export from the context menu. The export action in the tool bar and in the context menu of the method table export the method table without the currently shown graph.

  Please see the help on graphs with a time axis for help on common properties of graph views. The time axis in this case is the call duration axis.