Load Testing Blog
Distinct Think Time setting for Virtual User Pacing
Load Tester 6.7 includes a new option for Virtual User Pacing. When configuring Think Time Generators (Window > Preferences > Web Performance > Think Time), the new checkbox is labeled Distinct – Allow users to have distinct paces. This applies only to the random variation generators. When turned on, it changes how the random variation range is applied to think time.
When turned off, the think time generator will function as it always did – for each think-time encountered, it will vary the think time (as configured in the testcase) by a random value within the configured range. When turned on, … Continue reading »
Measurements plugin for SeleniumIDE is now available in the Firefox add-ons store
This Firefox extension is a plugin for SeleniumIDE that makes it easy to collect performance measurements during a test. Installing this extension will add new commands for starting and stopping timers and provides a UI for viewing and downloading the collected measurements.
ChrisWhen his dad brought home a Commodore PET computer, Chris was drawn into computers. 7 years later, after finishing his degree in Computer and Electrical Engineering at Purdue University, he found himself writing software for industrial control systems. His first foray into testing software resulted in an innovative control system for testing lubricants in automotive … Continue reading »
Site is slow under load, but the servers aren’t busy?!?
The problem
Here is the situation: We are running a load test for a customer. The web servers are showing low to moderate CPU utilization and low disk activity. They have plenty of memory available. The middle-tier servers are reporting similar measurements. So is the database. Everything looks good in the load test.
ChrisWhen his dad brought home a Commodore PET computer, Chris was drawn into computers. 7 years later, after finishing his degree in Computer and Electrical Engineering at Purdue University, he found himself writing software for industrial control systems. His first foray into testing software resulted … Continue reading »
Checking HTTP status codes from your Selenium/Java tests with the Meddler extension
Over the years, I’ve see a couple of questions repeatedly on the Selenium boards related to HTTP status codes: How do I check for broken links (404s)? How can I check the status code of a web-service request made from my web-app? The answer is usually “Selenium can not do that” because, of course, Selenium is a browser automation tool – not a full-featured testing solution. Other answers suggest various solutions…none that I’ve seen are elegant.
ChrisWhen his dad brought home a Commodore PET computer, Chris was drawn into computers. 7 years later, after finishing his degree … Continue reading »
Backup and Restore Chronograf Dashboards
Chronograf is a web-based GUI for visualizing time-series data, typically from a time-series database such as InfluxDB. I have been using it recently to store load-test measurements created by the MuseIDE Measurements extension.
I have been running it in the cloud, starting up a fresh instance whenever I have the need for storing load test results. This is handy and very cost-effective, but starting from scratch means that I need to set up dashboards of the metrics I want to see every time.
ChrisWhen his dad brought home a Commodore PET computer, Chris was drawn … Continue reading »
Introducing the Influx extension for MuseIDE
InfluxData offers a set of tools that are well-purposed for load testing:
InfluxDB is a time series database that is very good for storing measurements generated during load testing
Telegraf is a client that can report performance-related OS measurements to InfluxDB (CPU%, Memory%, bandwidth, network and disk I/O, etc). Useful for monitoring both the load generators and the servers.
Chronograf is a visualization tool for time-series databases – very handy for visualizing and analyzing load test measurements.
ChrisWhen his dad brought home a Commodore PET computer, Chris was drawn into computers. 7 years later, after finishing … Continue reading »
Measurements extension 0.3 now available
The 0.3 release adds some new plugins and enhancements applicable to performance and load testing:
New Test Plugins
The new Test Duration Plugin creates measurements of individual tests (# running, duration, etc.).
The new Step Summary Measurements plugin creates sampled measurements on steps such as success, failure and error counts, running count, running duration.
Enhancements to existing plugins
The Periodic Measurement Collector plugin can now tag measurements with the source hostname
The Step Duration Producer plugin has 3 new features for improving test analysis
The Save Measurements to CSV plugin now writes a footer line at the end of the file. The footer line … Continue reading »
Improved analysis with the Step Duration Producer plugin
Find failing steps
The Step Duration Producer plugin is part of the Measurements extension for MuseIDE. Its primary function is to report the duration of each completed step. Starting with the 0.3 release, it can add status metadata to each measurement indicating the completion status of the step – success, failure or error.
To enable, turn on the Add Step Status parameter in the plugin configuration.
With the status available, analysis or visualization tools such as Chronograf can identify which steps are failing in your test. This chart shows that a verify step failed 5 times:
Which steps are running?
Want to know which tests … Continue reading »
Test Duration Producer plugin
This plugin is part of the Measurements extension for MuseIDE version 0.3. It is a test-suite plugin that provides measurements to illustrate how many of each test are running, how long have they been running and how long did they take to complete. It is intended to be helpful for load testing.
Each time a test within a suite completes, a measurement is produced containing the duration of the test. If the running tests parameter is true, then each time measurements are collected by the Periodic Measurement Collector, two additional measurements are produced for each test. The first, running, is … Continue reading »
Analyze measurements by hostname
The Periodic Measurement Collector plugin, part of the Measurements extension for MuseIDE, now has the ability to add the hostname to each measurement it collects. This will allow analysis tools to analyze performance based on the source of the measurement. In the context of load testing, this would allow identification of regions that are experiencing slower page load times.
Here is an example of the durations of a homepage under load, identified by source hostname:
To enable this feature, turn on the Add source hostname parameter in the plugin configuration. Note that it applies to all measurements collected by the plugin.
This … Continue reading »