Load Testing Blog
Recording in Load Tester: What’s Going On?
Load Tester is designed to recognize common use patterns and transform them into working test cases with a minimum of user intervention. Our clients appreciate that Load Tester does a tremendous amount of work automatically. But, any load testing tool must be prepared to exercise the complexity of its target, and for some web applications even a simple test case can involve hundreds of variables.
This post will try to elucidate the stages of the recording process, which are, roughly:
Recording
Initial Inspection
Automatic Configuration
Manual Configuration
Replay
Validation
During the recording stage, we manually perform a use case in a web browser. Load Tester monitors our work … Continue reading »
The Fastest Webserver?
Looking for the snappiest, fastest web server software available on this here internet? So were we. Valid, independent, non-synthetic benchmarks can be difficult to find. Of course, we all know that benchmarks don’t tell us everything we need to know about real-world performance; but what’s the fun of having choices if we can’t pick the best?
Exactly. I decided to do a little research project of my own.
Test Plan
I selected for this exercise recent (as of October 2011) versions of Apache, Nginx, Lighttpd, G-WAN, and IIS — a list that includes the most popular web servers as well as web servers … 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 »
Web Performance 4.2 (beta) Migration Guide
This document provides details for users of Web Performance Load Tester version 4.1 who wish to upgrade to Web Performance Load Tester version 4.2. Load Tester 4.2 is more powerful and flexible than previous versions of Load Tester. For the most part, Load Tester 4.2 can automatically import and upgrade repositories that were written from previous versions. There are a small number of changes that existing users will want to be aware of in advance.
Once a repository has been opened in version 4.2, it will be impossible to open that repository in any older version of Load Tester. Load Tester … Continue reading »
User-Friendly Server Monitor Licensing in 4.2
At Web Performance we offer software licenses for two products: Web Performance Load Tester (also known as the “controller”) and the Web Performance Advanced Server Analysis module (also known as the “server monitor”). The controller is a user-friendly tool to create and execute load test scripts, while the server monitor is a headless tool that gathers diagnostic information about potentially problematic servers. Working together, these tools can quickly and efficiently identify specific problem areas.
Our belief is that software licensing should be as quick and painless as possible, which is why we designed the controller to automatically distribute licenses to all … Continue reading »
New feature: Run a Load Test from the Command Line
A number of customers have asked us about adding a load test to their automated nightly test harnesses. An early and frequent testing cycle is the quickest (and least expensive) way to identify problems — imagine being able to correlate performance results with specific revision numbers from your source control repository.
We already had the capability to run a single-user replay from the command line, but this week, we added support for running complete load tests, which will be available as part of the upcoming Web Performance Load Tester version 4.2. From the command line, it will be possible to:
Execute any … Continue reading »
Garbage Collector Performance under Load
The overwhelming majority of dynamic internet-facing applications are built on garbage collected runtimes such as Java and .NET. Garbage collection is popular because it promotes rapid application development. On the other hand, whenever a system is demonstrating unexpectedly poor performance, the garbage collector invariably surfaces as a possible suspect. Our advanced server analysis module even hooks into garbage collection performance monitoring on the .NET platform.
The reality, however, is that modern garbage collectors are very good.
Fact: Our company has been in business since 1999. In this time, no one can recall ever encountering a system with a performance problem that could … Continue reading »
Drupal: Caching and Database Scalability
Note: This is Part 4 of an ongoing series on Drupal performance and load testing. If you haven’t already, read the introduction.
Summary
We measured Drupal’s performance with respect to database size, demonstrating flat performance regardless of the size of the database. We also got some good data demonstrating Drupal’s behavior with caching.
Procedure
We re-created our previous test platform: a stock Drupal installation on an Amazon Elastic Cloud m1.large instance with both the Alternative PHP Cache (APC) and Drupal’s built-in caching capabilities. In this test, however, instead of scaling the number of simultaneous users, we instead held the test at 400 … Continue reading »
aiCache and Drupal: A Case Study
Note: This is Part 3 of an ongoing series on Drupal performance and load testing. If you haven’t already, read the introduction.
Custom Extractors in Web Performance Load Tester
This tutorial will outline the steps to configure a custom extractor in Load Tester. Extractors are used to recognize small pieces of data in your application and apply them to future transactions within a test case.