Probe Telemetry Comparison

  The probe telemetry comparison is one of the probes comparisons. It is created by invoking the probes comparison wizard. For more information on snapshot comparisons, please see the snapshot comparison overview.
  The wizard has the following steps:
  • Select snapshots
    The telemetry comparisons compare two or more snapshot files. In this step, you select whether you want to compare the snapshots that you have selected in the snapshot selector, or whether all snapshot files should be compared. The default selection depends on whether you have selected more than one snapshot in the snapshot selector.
  • Probe selection
    In this step, you choose for which probe the comparison should be made. If you select the "custom probe" option, all snapshots are analyzed to find out which custom probe are present in all snapshots.
  • Telemetry group
    In this step, you choose for which telemetry group the comparison should be made. Probes can publish one or more telemetry groups with multiple measurements each.
  • Comparison type
    Each snapshot file contributes one value to the comparison graph. That value can be the
    • current value
      This is the value when the snapshot was saved, i.e. the rightmost point in the telemetry view and the value that is displayed next to the legend entries there.
    • maximum value
      This is the maximum value during the entire time that the telemetry view was recording data. The maximum value is evaluated separately for each snapshot file.
    • value at a bookmark
      In JProfiler, you can set bookmarks for specific points in time. In addition, there are automatic bookmarks for recording events. If all compared snapshots contain a bookmark with the same name, you can compare values at those times. If you choose this option you have to select a bookmark from the combo box below. Only bookmarks that are contained in all snapshots are displayed.
  • Compared measurements
    In this step you select which of the measurements from the selected telemetry group that should be compared. You can select any combination of measurements.
  Any telemetry comparison behaves similarly to the probe telemetry views themselves, on the horizontal axis you see the snapshot numbers from the snapshot selector, the vertical axis remains the same. Effectively, the time axis from the VM telemetry views is replaced by an ordinal snapshot file axis.
  There are several view settings that influence the display of the comparison. Please see the help on the probe telemetry views for more information.