Testing practice

Load testing of HTTPS web sites
Testing practice WAPT usage

Load testing of HTTPS web sites

As you probably know, the percent of secure HTTPS web sites is growing every day. Moreover, even if you do not care about security, the latest news from Google suggests that you will have to move to HTTPS in any case, because otherwise you will see your site dropping down in search results.

Depending on the implementation of your site, switching it to secure connection may take from few minutes to few weeks. You may face functional problems, broken links and thigs like that. Imagine that after you have done everything required, you finally see your site working under the perfect green line of the browser address bar. The question is: what have happened with the site performance, and should you load test it again?

12 typical confusions for a novice load tester
General Testing practice WAPT usage

12 typical confusions for a novice load tester

After several years of work with our customers I decided to summarize my experience by gathering the most common user confusions resulted in questions to our technical support service. I think that most of these issues were caused by wrong ideas or interpretations people may have had. In other words, in each specific case the problem was caused not by the lack of information, but rather by some sort of incorrect assumptions.

Of course, nothing like that would be possible if everyone spent couple hours reading the user guide before trying to use the product. But for some reason people rarely do it this way.

Performance glitches on charts
Testing practice WAPT usage

Performance glitches on charts

When you load test a web application and gradually increase the number of virtual users during the test, you usually expect to see gradually degrading performance parameters such as response time. The number of pages (sessions or hits) per second will reach maximum in some moment and will probably stay the same for the rest of the test despite the growing load. This is simply because the site cannot serve more requests per second, so it has to postpone the new coming ones.

In reality you will probably see something like that, but only for a limited time. When the load goes even higher, you can get another picture that may seem surprising at first glance. It is illustrated by the following three charts. Black line in all charts represents the number of virtual users.

How to analyze a load test report? Part 4: Response time.
Testing practice WAPT usage

How to analyze a load test report? Part 4: Response time.

Let’s suppose that you have already resolved all problems related to unexpected errors in your test. I mean that your site may produce some errors on heavy load, but the emulation of the user sessions is performed correctly and the error rate is acceptable. If this is not the case, or you have any doubts, you may want to read my earlier posts here and here.

If the errors are not an issue, your next step is to look at the most evident indicator of the application performance – its response time. This term initially refers to a time required for your application to respond to a user action. This looks very simple, but you should keep in mind the following things, if you want to analyze the test results correctly.

How to analyze a load test report? Part 3: Errors.
Testing practice WAPT usage

How to analyze a load test report? Part 3: Errors.

If you see any errors after executing a load test, first of all you should check if this is a test design problem. I wrote about the most typical problems of that kind here.

Now let’s suppose that the test was designed correctly and any errors we see in the report are related to the load you created in the test. In other words, I would like to talk about errors that appear because of performance problems, not anything else. If you are not sure why an error takes place, try running the test with same profiles and a smaller number of users, and see if the same problem appears.

First of all I should note that there are different types of errors.

WAPT Cloud: New benefits of our load testing solution
General Testing practice WAPT usage

WAPT Cloud: New benefits of our load testing solution

In the last days of 2013 we released a cloud version of our load testing solution. It is based on WAPT Pro, all extension modules and x64 Load Engines, so it is the most feature-reach and powerful combination of all the components we have.

This on-demand load testing solution is offered through the Amazon EC2 Marketplace. This means that with few clicks you can get the full functionality of WAPT Pro running on a virtual system instance in the Amazon Cloud. To do this you need to have an AWS account, however it is also very easy to create one. We provide step by step usage instructions right from our web site.

Some experienced users already know that all our products can be used in any cloud or virtual environment. So, technically this release is not a big step forward. With new cloud version it is easier to start and configure the product, but this is not the actual benefit. What really makes the change is the pricing for the new solution, which is now based on the hour rates.

How to analyze a load test report? Part 2: Test design problems.
Testing practice WAPT usage

How to analyze a load test report? Part 2: Test design problems.

When you start load testing a web site (especially if this is the first load test in your life) you may see a lot of errors in the report. Possibly you will even have to stop the test before it completes, because at some point in time it becomes clear that something goes wrong. If the problem is not so obvious, it is still recommended to check the report for the errors related to each virtual user profile (i.e. to each different type of virtual users) before looking at any performance data.

Usually you do not create a high load in the very first test of a web site, so if you see any errors in the report, most probably they appear because of the test design problems. In other words, the emulation of the real user activity is performed incorrectly. Your web application may produce errors and even refuse connections because it receives incorrect data from your load testing tool. Why this may happen?

Extreme online shopping with WAPT Pro
General Testing practice WAPT usage

Extreme online shopping with WAPT Pro

Recently we have discovered that our load testing solution can be applied in a quite unusual way. One of our users has shared his “success story” with us. It perfectly shows how widely you can apply the product if you know its features very well and have a good fantasy.

The story is actually about Cyber Monday online shopping. You know, some web sites run very special actions to attract customers. They sell limited number of items at exceptionally low prices. In theory you can make a very good deal if you participate. In practice this is almost impossible, because each new item is ordered by someone immediately after it becomes available. Here is where WAPT Pro appeared to be a great automation solution.

Load testing a mobile website for iPhone
Testing practice WAPT usage

Load testing a mobile website for iPhone

While mobile devices are replacing PCs for almost all possible applications, the Internet is also changing to address this technology shift. On the other hand, despite the unbelievable progress in the performance characteristics of smartphones and handheld computers, they are doomed to stay different from PCs by one parameter: screen size.

That is why most web sites offer different content when they are visited from a mobile device.

Of course, this content is usually just a reduced version with a very similar functionality. However the implementation of the underlying web application can be different.

As a result, your web site can experience significantly different performance problems when it is accessed by multiple mobile users.