Session comparison

AppMon provides advanced session comparison functionality for diagnostic analyses.

The following analysis dashlets support comparison:

A differential diagnostics analysis that is executed on two sessions, referred to as the main session and the compare session, is processed in the following way:

  1. For each session, the corresponding regular diagnostics analysis is executed.
  2. The results of these two analyses are matched against each other.
  3. All matched and all unmatched records form the output of the differential analysis.

The differential analysis is not based on session data directly, but acts as a layer on top of the regular analysis. This allows a comparison of sessions located on different AppMon Servers without any connection between them. The comparison of the two intermediate AppMon Server results is done on the client.

When two records are matched, their characteristic values are checked for equality. A record's characteristic values correspond to its static content, such as an API Breakdown analysis record name, as opposed to the variable content, such as the timings.

While the static content of a differential result record is displayed unvaried, the variable content is presented in the following way:

difference ( percentage % )

where:

difference = mainValue ‐ compareValue  
percentage = ( difference / compareValue ) * 100

Take note of the following:

  • Comparing two empty values ( - ) yields an empty difference and value:  - (-%).
  • If only one value is empty, it is treated as 0, but no percentage is displayed: xyz (-%).
  • Sorting is based on the difference value, because this usually gives a better idea of the relevance of a given difference among all other values.
  • Shading is based on the percentages, with negative values in green and positive values in red. The higher the values are, the more saturated the colors.
  • If a record cannot be matched, it is shaded in gray and displays only the difference relative to 0.
Example session comparison
Example session comparison

Usage

This section first explains how to configure the comparison settings, then describes the available comparison display variants.

Configuration

Session comparison can be set globally for a dashboard in the dashboard's configuration. It can also be set for each dashlet, overriding the inherited dashboard configuration.

To configure the comparison, open the Properties dialog box for the dashboard or the dashlet, and select the Comparison tab. The comparison data source can be configured just like the main data source in the Source tab, but is completely independent from it. None of the filter criteria applied to the main data source, either dashlet-specific or inherited, are applied to the compare data. However, filters for the compare data can be configured just like the regular filters, and inherit any configuration from the dashboard's compare filter.

The following figures show the Comparison tabs for dashlet and dashboard.

You can copy the main data source settings including the filter setup from an open dashlet by clicking Copy from and selecting an entry.

The entry shaded in gray is the dashlet that is being configured.

Copying Comparison Settings
Copying Comparison Settings

Comparison display variants

All dashlets that support comparison can switch the data being displayed. Besides displaying the results of the differential analysis, a dashlet can show the results of the two regular analyses.

To switch the display, select Comparison from the context menu as shown below.

The currently displayed data has no further influence on the behavior of the dashlet. When you refresh the dashlet, the two primary sources are analyzed again and the differences computed.

Context Menu - Comparison
Context Menu - Comparison