Load Testing Blog
Bandwidth, latency and geographical distance in load testing
Because we usually talk about latency in tiny numbers (e.g. 20 milleseconds of latency) it is easy to overlook just how big an effect latency can have on the effective bandwidth between geographically distant locations. While running some recent tests to measure the available bandwidth from our cloud engines, I accidentally ran a test between a load engine and a server that were more than 2600 miles apart. Knowing that our server and engine should have both delivered better results, it took me a few minutes to realize that one mistaken click (where to start the load engine) had … Continue reading »
Javascript/JSON Support in Load Tester 4.3
Over the last year, Web Performance engineers have been working to make Load Tester smarter and easier to configure. Load Tester 4.2 introduced the new Fields View, which allows test case developers to write out HTTP requests using a flexible and composable assortment of data sources.
Starting with Load Tester 4.3, Load Tester will automatically recognize JSON content in any HTTP request. As a consequence, each JSON element will become a configurable name-value pair field in the Fields View. We believe this will make it much easier to configure complex AJAX and RESTful style test cases.
Furthermore, whenever Load Tester’s Application … Continue reading »
Monitor Unlimited Web Servers with Server Monitoring Modules
Now if you have even a single server monitoring license you can monitor an unlimited number of servers at no extra charge! The Server Monitoring modules are add-ons for Load Tester that add the ability to monitor a couple dozen different parameters from the Windows or Linux operating systems or the .NET application server. Previously they were licensed on a per-server basis, which meant a license had to be issued for each server, and customers who purchased a bunch had the hassle of managing a handful of licenses, each of which had to be installed and updated.
In … Continue reading »
How much bandwidth can we expect from cloud engines during a load test?
I got into a discussion in the Performance Testing group on LinkedIn which raised a question that we had answered internally, but had neglected to share with our customers – how much bandwidth do our cloud engines have available?
Before I proceed, I must make this disclaimer: our cloud engines run on Amazon’s EC2 infrastructure, so the rules that apply there also apply to our cloud engines. Amazon does not make any guarantees for bandwidth, so anytime your test results look suspicious, we recommend doing a quick bandwidth test. Note that there is a Bandwidth Test wizard in Load … Continue reading »
Changing Recorded hostnames & URLs in Load Tester
From time to time we get support questions from customer asking us how to update a recorded testcase to a different URL without having to re-record the testcase. If the content of the new URL/server is very similar to the original URL/server, then a re-recording of the testcase may not be necessary. Simply updating the recorded URLs with the new URLs should be all that is needed to get the original recording working with the new URL/server. Below are the steps on how to update recorded URLs in Load Tester 4.2.
Updating recorded URLs
In order to change the transaction URLs, switch to … Continue reading »
Load Test development using proxy servers improved for Load Tester 4.3
Proxy servers are nothing new to corporate users, and Load Tester has supported test development through a proxy server for those testers that were required to use one. However, we’re excited to introduce two new improvements to Load Tester’s proxy support for Load Tester 4.3: more detailed recordings and replays of proxy traffic, and support for proxy authentication.
In all versions of Load Tester, it is possible to change the proxy configuration, and then play an existing testcase correctly using the new proxy settings. Since proxies may require the use of additional HTTP messages to create a tunnel and / or … Continue reading »
Enhanced Integrated Windows Authentication Support in Load Tester 4.2
Load Tester 4.2 offers a substantial number of enhancements over the 4.1 release. One of the last features, which was not available in the 4.2 beta cycle, is completely redesigned support for Connection Authentication Negotiation. For IIS users, just think of “Connection Authentication Negotiation” as support for IIS’ “Integrated Windows Authentication”. Load Tester’s CAN support is a bit more abstract to encompass other servers as well. In fact, the term “Connection Authentication Negotiation” is used to provide support for negotiation of an authentication scheme at the HTTP layer, which may be used to authenticate the browser’s connection to the … Continue reading »
How HTTP Authentication works and why load testers should care
The most commonly used authentication method for websites is a login form on a web page. We’ve all seen them – enter your username and password into fields on the web page and press the Submit or Login button. From the standpoint of the underlying technology, this is no different than submitting any other form – only the names of the fields distinguish them as login or password fields and the security mechanism is implemented within the web application.
Web Performance Consulting
Our experts … Continue reading »
How to upgrade NTLM testcases from Load Tester 4.1 to 4.2
Due to the scope of changes in the 4.2 release and the improvements to our NTLM support, testcases using NTLM that were created in Load Tester 4.1 and earlier versions are not automatically upgraded with the required 4.2 configuration settings. The result is testcases that will not be able to perform the NTLM authentication – therefore causing a failure of every transaction that requires authentication. Fortunately, the manual upgrade process is relatively easy:
Step 1: Select the testcase and run the Testcase Configuration wizard. You can do this from the pop-up menu in the Navigator view (Configure > Configure for Replay) … Continue reading »
What’s new in Load Tester 4.2
The 4.2 release focuses on platform compatibility and productivity increases from our services work in the past year with such clients as the US Census and the New York Marathon.
With a slew of new browsers and operating systems available, this release also includes support for 64-bit Windows and AIX operating systems, the latest versions of Internet Explorer, as well as the Chrome and Safari browsers.
On the productivity side there are some pretty big changes to allow testers to configure more complex testcases with less effort than ever before. Some of those changes are evident in the new Fields View and … Continue reading »