We recently had a case of debugging a testcase where Load Tester reported an error with a page that looked and appeared just as it should, except it was missing a link the user needed to move forward. Debugging this case was easy: examine the replay two pages prior to the error, and the server had added a red error message to the page indicating the selected criteria was not valid.
So why didn’t Load Tester flag this error from the server? Beneath the error message, the page was exactly identical to the expect page: form fields were present and filled … Continue reading »
When I first started writing test cases with Load Tester, I found it easy to fall into the psychological trap of writing functional test cases. But load testing requires a different approach, and inadequate tests can cost you time and money.
Functional test cases (such as the unit tests popularized by JUnit) confirm the correctness of a system. These tests should be highly specific and have excellent code coverage. A good engineer approaches functional testing as though she were designing a jet engine: if any screw, flange, or circuit fails then the entire system is completely … Continue reading »
There are a few errors that are frequently reported by customers. One of them being the missing user variables error. A missing user variables error basically means that a variable that was suppose to be extracted on an earlier page was not extracted, and the user is now trying to use that variable. The error can be caused by a number of things, the most common are server connectivity issues and improper configuration of a dynamic value.
If the missing user variable error was caused by server connectivity issues, there tends to be a server error before … Continue reading »
With Load Tester 4, we’ve made it easy to harness Amazon’s power for Load Engines quickly and inexpensively. Once you’ve familiarized yourself with the basics, here are a few rules of thumb:
1. Get to know the Amazon EC2 Console . The console will quickly tell you what instances you have running – and subsequently what you are getting billed for.
Note that the console shows you only data for a selected region, so you should check each region separately. Load Tester will automatically prompt you after a test and before shutting down Load Tester if you have running engines … Continue reading »
One of the common questions our customers ask is: “should we buy software and do the load testing ourselves or hire someone to do it?”.
The question is one with few easy answers, but in this blog entry I’ll lead you through the thought process so you can decide which option is the best for your situation.
The first question to ask is how often do you need to do load testing? If you’re planning on testing more than twice a year its usually cost effective to purchase software and learn how to use it. This is true of … Continue reading »
Maybe you’ve just finished your first crack at testing, handed some results up to the development team, and are just got a note that the dev team has revamped the site in preparation for the next test. Or maybe you completed testing last month and are ready to retest the site against any regressions. Are all the testcases setup from the last round of testing still going to work? Are you going to have to create all new testcases? Here are a few quick ways to find out:
1. Run a replay with your existing testcases. If the replay fails … Continue reading »
The website is completed or mostly completed and you have been advised to do a load test, but you are not quite sure were to begin. First things first, a basic understanding of load testing procedure is needed. The load testing procedure mostly involves understanding the web-application that will be tested. Understanding the applications refers to many different factors such as:
Understanding the functionality of the website.
Understanding the general network layout.
Understanding the software and hardware used by the system.
These factors are useful for a number of reasons, not only do they make the load testing process easier, but they can help … Continue reading »
Load Tester is a web site load testing tool, and as such we deal primarily with the most popular Internet communications protocol: the Hypertext Transfer Protocol, or HTTP, which controls the request and transmission of web pages between browser clients and web servers. HTTP is based on a lower-level protocol known as the Transmission Control Protocol, or TCP. For the most part, TCP works in the background, but its proper function is critical to your website, and problems at the TCP level can show up in many different ways during a load test. … Continue reading »
An experiment by a vendor of website accelerator appliances showed that optimization of website performance had a measurable improvement on visitor retention. Visitors to the optimized site:
had a 1% lower bounce rate
visited 4.5 more pages
spent 27% more time on the site
For the retail site they tested, the impact was felt on the bottom line:
conversion rate increased 16%
order value increased 5.5%
For details, read the full article: Proof that speeding up websites improves online business.
Chris, Chief Engineer
ChrisWhen his dad brought home a Commodore PET computer, Chris was drawn into computers. 7 years later, after finishing his degree … Continue reading »
With the release of Load Tester 4.1, we’ve been discussing some of the new features available in this release. One of those features is Simulated DNS Load Balancing. This feature offers improved testing accuracy over previous versions of Load Tester.
This feature is designed for systems which may use DNS to alias a single hostname to many different IP addresses, allowing the DNS system to provide load balancing. This works effectively when the users or load engines greatly outnumber the number of servers, and are well distributed and not in a common location. For users that wish to test their system … Continue reading »