Load Testing Blog
How-To: Dynamic Field Names and Multi-Variable Extractors
Overview
You’re recording test cases, configuring them, replaying them, and running load tests. One day, you attempt to test a new web application. However, every time you attempt to run a replay, the replay throws an extractor error; it is unable to find a field in the page content of the replay to extract. ASM configured this field automatically, so why isn’t it working? You look at the replay content … and the field name isn’t there.
The usual culprit that causes this problem is a dynamic field name: a variable in a dynamic web page that not only changes in value, … Continue reading »
Estimating Load test ramp-up times
How long should my load test take? How quickly should the test ramp-up users? Is there a right answer, or a wrong one?
Performance Goals and Analysis Methods
We are getting close enough to the 3.6 release that I’m able to talk more about the new features – so look for more posts in the next few days. I blogged previously about the improved performance goal features, but at the time, I could not detail how they would be used to improve Load Tester’s analysis reports.
Search view added for Load Tester 3.6
As web applications become more sophisticated, configuration of testcases used to test the application becomes more difficult. The need for customization, beyond the automatic configuration provided in Load Tester, means that testers need to spend more time understanding the application. One common scenario finds the tester searching through the application pages to determine where a field is assigned, in order to configure a custom extractor to get the value dynamically. Several of the features added in Load Tester 3.6 makes this process much easier.
In the example below, the Search View is used to find a field with dropUsers in the … Continue reading »
Sharepoint Performance Case Study
Is your Sharepoint website slow? Are the servers under-utilized and the database shows no locking, but response times for the pages are still poor? Is Sharepoint unstable under load? We recently helped a client through the grueling process of optimizing and stabilizing a large Sharepoint installation. Once we discovered the underlying causes, the fixes were rather easy, but finding the performance bottlenecks was time consuming. We’ve described the process and the findings, so you can skip the hard part!
Read the case study.
Virtual User Calculators
Customers frequently ask us for help deciding how many virtual users they need for their load tests. We have a number of formulas for calculating this, depending on what information the customer has available. Last weekend I built online calculators for a few of the more popular variations. Give them a try!
If these don’t apply to the data you have available, contact us and we’ll be happy to help you calculate the number of simulated users required for your specific needs!
Measuring the Performance Effects of Dynamic Compression in IIS 7.0
Enabling dynamic compression in IIS 7.0 can reduce the bandwidth usage on a particular file by up to 70%, but also reduces the maximum load a server can handle and may actually reduce site performance if the site compresses large dynamic files. Read the full report for a complete analysis.
Measuring the Performance Effects of mod_deflate in Apache 2.2
Enabling mod_deflate can reduce the bandwidth usage on a particular file by up to 70%, but also reduces the maximum load a server can handle and may actually reduce site performance if the site compresses large dynamic files. Read the full report for a complete analysis.
Is the last mile relevant to Load Testing?
One of our competitors has recently been emphasizing the use of their monitoring network during load tests. The pitch goes something like this: “With our last-mile monitoring network you can determine how different geographical regions will experience your web pages.” This solution has been implemented by using testing agents in the homes of real consumers to measure performance during a load test.
At first glance, this peaked our interest. However, after some analysis, we started to question the real value of this approach to load testing:
Will this approach dilute the value of the load test results?
Can the same information be obtained … Continue reading »
Load Tester improvement – better success and fail metrics
Previous versions of Load Tester had 2 metrics describing the success or failure of a web page (or single transaction) during a load test: Repeats and Errors. A Repeat was counted any time a valid HTTP response was received from the server. Errors, however, were a bit more complex. Errors could occur at any point in the transaction, from establishing a connection to post-response validation. An error was counted if the connection was terminated in the middle of a transaction. It was also counted if the status code from the server indicated a failure (e.g. a 500 status). Validators record … Continue reading »