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 »
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 »
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 »
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 »
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 »
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 »
One of the challenges in running a large load test is the orchestration of a large number of machines to generate load. This involves a series of steps:
Creating the instances
Install the load testing software
Sending the test configuration
Run the test
Collect test results
Shutdown the instances
Load Tester does that pretty effortlessly in EC2 – our customers as well as our own test engineers love not having to worry about those steps. It just works. As I evolve our next generation of testing tools, I am revisiting this problem and looking at solutions from a different angle. Last week, I decided to investigate … Continue reading »
For Rowan University, ensuring that their students can get registered for classes is not an academic problem. If errors or system crashes prevent students from getting into the classes they need, it can have a serious impact on their academic careers, potentially even resulting in additional educational costs. So when the IT wizards at Rowan were planning significant upgrades to their hardware and the Banner 9 software from Ellucian to ensure the best possible experience for their students, they knew load testing was an essential part of the project.
It has been 99 years since a solar eclipse has crossed the entire continental US, coast-to-coast. 14 states will be treated to 2½ minutes of total darkness by the August 2017 eclipse. I remember watching the partial solar eclipse of February 1979 in my school playground. I am (obviously) a little bit of a science geek, so when I got the assignment to load test the Eclipse Live 2017 site, I was excited. Besides the prestige, it’s really fun to be associated with a project that will be seen by millions, even in a minor role.
NASA hosts much of … Continue reading »
When Load Tester record a testcase, it impersonates the website – the browser thinks it is talking to the website but it is actually talking to Load Tester’s recording proxy. For this to work with SSL, Load Tester has to provide a certificate that impersonates the website. These are auto-generated on demand and stored within the project workspace.
Starting in version 58, Chrome has dropped support for the Common Name (CN) field in a certificate. In this case, the Common Name field tells the browser what domain name the certificate applies to. This field has been deprecated and replaced by the … Continue reading »