Metrics summary graph in JBoss ON is misleading

Environment

• Red Hat JBoss Operations Network (ON) 3.2, 3.3

• Resource measurement that is collected periodically and never has a value of 0
• Reviewing the metric summary chart for a time period that would include less then 60 collections of the metric -- For example, if Max Pool Size is collected every 20 minutes and you click on it in the metrics monitoring page to view its summary chart for the last hour

Issue

• Metrics summary graph is misleading
• Metric summary graph line will drop to 0 in between two collection points although metric value is constant and not equal to 0
• Metric summary graph shows spikes with the correct value at the collection point but drops to 0 in between two collection points

Resolution

This has been logged as This content is not included.Red Hat Bugzilla 1236021 and an enhancement will be considered for a future release.

In the meantime, it is important to realize that the metric summary chart will display periods that fall in between actual collected data points as 0. The metric bar graph is not impacted by this issue as it displays periods with no data as vertical dashed lines that extend the entire height of the graph.

Root Cause

When the summary graph is generated, all collected values for the measurement are plotted on the graph. However, when the time period is broken into equal segments for normalization and display, the areas between the collection points have a value of NaN. This value is being displayed on the chart as 0 resulting in misleading representation of data that seems to drop to 0 at a predictable interval.

Diagnostic Steps

• Steps to Reproduce:

  1. Add to JBoss ON inventory RHQ Server resource (if it's not added already);
  2. From JBoss ON UI -> navigate to RHQ Server resource -> Subsystems -> Connector -> datasources -> DataSource(Standalone) -> Monitoring -> Schedule
  3. Change Max Pool Size collection period from default 4h to 20 minutes;
  4. After an hour, navigate to DataSource(Standalone) resource -> Monitoring -> Metrics -> and click on Max Pool Size to open a graph

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