Real Time Monitoring

How to Watch Performance Data Instantly in Your Graphite Instance

While a load test is running, the master controller only shows basic information about the load test status. In interactive mode, you could at least download intermediate results and generate a report to see how the test is going. In automated environments, however, you would have to wait until the test run is finished before you can actually do so.

Wouldn’t it be great if you could watch the results in real time and see how the performance varies over time while the test is still running? To this end, we have added the support of Graphite, a well-known data collection and graphing tool. During a load test, XLT could push selected metrics to Graphite. Using Graphite’s graphing capabilities or another graphing/dashboard tool on top of Graphite, you can watch the most important performance data instantly:

Load Testing Dashboard

See below for the XLT settings needed to enable and configure real-time reporting:

## Whether real-time reporting is enabled (default: false).
xlt.reporting.enabled = true

## The time period [s] after which updated metrics are sent to the 
## reporting system (default: 5).
xlt.reporting.interval = 15

## The text to be prepended to the name of any reported metric (default: "").
## Use this prefix to create a separate metrics branch for each XLT load test
## project in your reporting system.
xlt.reporting.metricNamePrefix = xlt.MyProject.

## The Graphite Carbon server's host and port (default: localhost/2003). = my.graphite.machine
xlt.reporting.graphite.port = 2003

If enabled, XLT reports the following metrics to Graphite:

  • runtime statistics (in total and per name), errors (in total and per name) and counts (in total) for
    • transactions,
    • actions,
    • requests, and
    • custom timers,
  • arrival rates (in total and per transaction name),
  • bytes/sent received (in total and per request name),
  • event count (in total), and
  • agent metrics such as the total CPU usage and heap usage.

Since not all performance details are sent to Graphite, you will only get a first impression of the application’s behavior. For a detailed analysis, the load test report is still the tool of choice.

Page load timings in Graphite

In older versions of XLT, page load timings were reported as custom timers to Graphite. Since XLT 4.12.0, page load timing data is promoted from custom timers to a dedicated data type (a bug caused the data not to be sent to Graphite at all before this was fixed in v5.1.2).

This data is stored to the “pageLoadTimings” subtrees. The bucket name structure for both specific page load timing records and summary records is similar to that of actions and custom timers. See below for an example how page load timing data is reported to Graphite:

xlt.Posters.ac001.pageLoadTimings.Homepage__FirstContentfulPaint_.errors 0 1592575693
xlt.Posters.ac001.pageLoadTimings.Homepage__FirstContentfulPaint_.runtime.max 543 1592575693
xlt.Posters.ac001.pageLoadTimings.Homepage__FirstContentfulPaint_.runtime.mean 543.00 1592575693
xlt.Posters.ac001.pageLoadTimings.Homepage__FirstContentfulPaint_.runtime.min 543 1592575693
xlt.Posters.ac001.summary.pageLoadTimings.count 18 1592575693
xlt.Posters.ac001.summary.pageLoadTimings.errors 0 1592575693
xlt.Posters.ac001.summary.pageLoadTimings.runtime.max 543 1592575693
xlt.Posters.ac001.summary.pageLoadTimings.runtime.mean 270.17 1592575693
xlt.Posters.ac001.summary.pageLoadTimings.runtime.min 20 1592575693
Last modified March 4, 2022