Load Testing Blog
Load Testing an Javascript or AJAX Application
Most of us are relieved that web applications are starting to behave more like desktop applications – i.e. smarter and easier to use. A little wow factor here and there doesn’t hurt either. Ease of use always has a cost, so it should come as no surprise that the AJAX applications are more difficult to develop. But you may be surprised that they can also be more difficult to load test.
The reason is fairly simple. Traditional web applications are relatively easy to model and simulate. The state of a user session, at any given time, is a combination of the … Continue reading »
Load Tester PRO™ 5.1 Released
Fast on the heels of the initial 5.0 PRO release, 5.1 is a major upgrade that includes support for mobile load testing, a completely resigned load test design and control system, improved support for dynamically scalable websites, Internet Explorer 10 support, and portal license manager integration.
Mobile Load Testing
The increasing web traffic from mobile devices has been noticed for years, but how much does it really affect a website? A recent study shows that 7% of web traffic is from mobile devices, which includes both phones and tablets. Because these devices use different browsers, and sometimes access different versions of a … Continue reading »
Do NOT cheat on VUs!
Because load testing tools are usually priced by the number of simultaneous users it can generate, it is tempting to lower the think time or increase the simulated bandwidth and run the test with a lower number of VUs than needed. Then, estimate the number of users the system can handle based on this scaling this (flawed) data.
There is a subset of systems for which this is acceptable. These are primarily sites serving stateless static content or very atomic web services on systems extensively engineered for scalability. Unless your system falls into one of these very narrow categories, then DO … Continue reading »
Load Test the Production System
There was a time when the common wisdom accepted that testing a production system was a bad thing. The reasons vary and many still follow that belief. We, however, test production systems for our clients more often than not. Not only can it be successful, we believe it is critical!
We have heard lots of reasons for NOT testing production systems. For example:
It is a 24/7 system, so we can’t take it down.
We can not risk degrading the performance of real users.
We cannot test it live because test data will corrupt the database.
System has to be available 24/7? No need to … Continue reading »
iPad or iPhone iOS Load Testing
With the rapid growth of tablets and smart phone purchases, the popularity of mobile browsers have increased significantly. Our own site has seen an increase in mobile traffic from 0.2% of two years ago, to 2.5% mobile traffic today. Due to the increase in popularity of mobile browsers, it is becoming essential to test the performance of your website on a mobile device as well.
Web Performance Load Tester records all the HTTP traffic between the browser and server through a transparent proxy, this allows for Load Tester to be flexible with the types of browsers that can be emulated during a … Continue reading »
Why you should not cheat on VUs
Because load testing tools are usually priced by the number of simultaneous users it can generate, it is common to use fewer VUs (virtual users) than called for by the test plan. To compensate, testers may lower the think time (the time between pages) in order to move VUs more quickly through the testcases and achieve a higher transaction rate than actual users would produce. The transaction rate may also be increased by raising the simulated per-user bandwidth – again to speed the lower number of VUs through the testcases more quickly. The system capacity must then be extrapolated based … Continue reading »
Simplified pricing for Load Tester 5
Short version:
The pricing for Load Tester 5 has been simplified down to a single price for Load Tester 5, along with a handful of options. Easy to understand, easy to afford, easy to buy!
Long version (or, how I learned to stop worrying and love simple pricing):
We have always tried to make Load Tester easy to understand and easy to buy. Part of that effort was to offer flexible pricing based on what customers needed. Over the years, we increased the number of price tiers, added a variety of permanent, floating and temporary licenses. Somewhere along the way, our price … Continue reading »
Generating 1,000,000 Concurrent Users with Load Tester 5
Can Load Tester really generate 1,000,000 concurrent users? Many of our existing customers have run tests in the 20,000-50,000 range. With previous versions of Load Tester and some internal tools, our services group has run tests as large 600,000 VUs. But none of these tests really pushed Load Tester to it’s limits. We’ve engineered Load Tester from the start to scale, and scale big. All indications made us confident that our load generation infrastructure could scale far beyond any test we had run. However, the UI was not quite up to the task. Controlling the large number of load engines … Continue reading »
HowTo: Generate 1 Million Virtual Users with Load Tester 5.0 PRO
Leading up to the release of Load Tester 5.0, the Web Performance development team focused heavily on improving our capability to run massive load tests. Today, Load Tester 5.0 is specifically engineered to deliver as many as 1 million virtual users while controlling 500 remote load engines.
This is a “how to” article for Load Tester 5.0 users wanting to run their own massive load tests.
Before you Start
There are a few things you absolutely need. First and foremost is a modern workstation for the controller. By modern, I mean a 64-bit architecture with at least 7 GB of working memory. … Continue reading »
Utilize Monitoring Tools During the Load Tests
Load testing tools will report the performance of the system from the end-user perspective – i.e. how long pages take to load in the browser. This information crucial for determining if the site has a performance problem, but does not give a complete picture – it does not tell you why the site is slow. For that, you need performance data from your servers. This will allow you to, for example, correlate periods of slow response time to periods of high CPU utilization. Or find that the number of connections to the database server rises dramatically right before a flurry … Continue reading »