Load Testing Blog
How To: Run a Load Test to rule out Bandwidth Limitations
Bandwidth can be critical to the performance of a website. Since this is a rather obvious fact, it is common for our customers to watch for bandwidth as the limiting factor early in a testing effort. This is especially true when the load test results do not point immediately any other limitation, such as 100% CPU on the application server.
When faced with a poorly performing system but no obvious signs of limitations, it is natural to focus all energies on finding the cause of the problem. This might mean spending hours poring through firewall and router configurations, looking for anything … Continue reading »
User Capacity Analysis
How to measure the maximum capacity of your website in terms of concurrent users.
Checklist: Is your Load Test ready to run?
Here are a few quick pointers for checking your Load Test, to see if you are ready to run. Feel free to check back, as this list may be updated from time to time.
Test Planning:
Have the appropriate parties been notified of the test?
Do any of the servers have scheduled jobs during the test window? Automatic backups or other maintenance windows that are scheduled during normal down-time or idle-time can have surprising results during a high volume test.
Is the firewall going to be an issue? When using a small set of external IPs to generate load, make sure the firewall administrators … Continue reading »
Using Elastic IPs with Amazon EC2 cloud-based load engines
Amazon’s Elastic IPs provide an easy way to assign a fixed IP address to cloud-based load engines – which would typically have a different IP address each time one is created.
Moving Load Tester™ To A New Computer
If you’ve installed Load Tester™ on a workstation, and are in the process of upgrading to a new workstation, you may be wondering how to move your Load Tester™ installation between the workstations. For version 4.0, this is not a difficult process, and generally can be completed in four steps:
Install a copy of Load Tester on your new workstation. New installers are available at www.webperformance.com/download
Copy the .WPT files from the old workstation (if they are not already saved on a network share). These files contain your recorded & configured testcases, as well as load test results.
Transfer your License … Continue reading »
Solving Server Problems with the Waiting Users and Average Wait Time Metrics
Learn how to diagnose the tricky situation where a server periodically hangs on pages.
User-Level Analysis of Performance Results
By analyzing data against applied user levels, rather than only against elapsed time, Load Tester permits better understanding of performance and of capacity.
Load Testing Fallacies: It’s Not Ready for Testing
There is a new Load Testing 101 post over on the Dynatrace Blog. Overall, I think it is a pretty good article. However, it illustrates some of the fallacies of load testing that we hear from time to time. In this article, I want to dispel a fallacy that might be inadvertently reinforced by that post. Please note that I don’t want to speak for the authors – so I encourage you to read their article and judge their meaning for yourself.
Removing Ad-servers and Click-trackers from your Load Test
We field a lot of questions about load testing websites with 3rd party components on the pages containing advertisements or user tracking mechanisms. For many of our users, we recommend leaving these out of the load test entirely. For some users this causes some concern over maintaining the realism of the load test. In this post, I’m going to discuss the advantages and disadvantages of dealing with these in a load test – and then provide some quick instructions for easily keeping these services out of your load test.
I’ll start by looking at the possible advantages of including these services … Continue reading »
Velocity Conference – Day 1
My first day at Velocity was long, but fun. I breathed a sigh of relief when my luggage finally arrived…10 hours after I did.
I attended part of a Load Testing workshop early in the afternoon that raised some interesting topics:
Why are steady ramps bad? They showed some examples of how this approach can result in the wrong conclusions about system capacity. I agreed heartily – I’ve blogged on the merits of a stepped ramp in load tests previously.
Abandonment rates – This is a feature that I’d like to get into Load Tester sooner rather than later. A basic … Continue reading »