Load Testing Blog
How to Develop a Robust Load Testing Plan
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 »
Load Testing Back to Basics: Missing User Variables Errors
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 »
A Unique Browser approach to Fast: Opera Turbo
We’ve seen that modern browsers have made great strides to improve efficiency in rendering and javascript performance. But, the differences seem to be less noticeable when the network is stubborn. On a recent trip, I ran into just this problem. During the evening, the hotel’s local Wi-Fi seemed at peak capacity, the DNS servers were sluggish, and just getting connections opened often added a couple seconds. Getting onto common sites like Slashdot seemed to take 30 seconds or more from the overburdened local connection.
This seemed like a golden opportunity to try out one of Opera’s new features: Opera … Continue reading »
Configuring File Downloads
In most cases Load Tester handles a file download during a testcase automatically. Fundamentally, there is no difference between downloading a spreadsheet or an image on the page. But in some cases, Load Tester does not automatically handle the dynamic URLs used in certain situations. Most commonly, these are cases where the file is being generated on-demand and is assigned a unique identifier that is part of the URL path, rather than a query parameter. In these cases, because there is no unique identifier that can be used to locate the value (i.e. a form field name or query parameter … Continue reading »
Load Tester for 64-bit Windows on the horizon
We are well into the development schedule for the next release of Load Tester – version 4.2. There are a number of great new features on the way as well as some enhancements to our underlying architecture that will enable Load Tester to handle far more complicated testcases in future versions.
One of the features coming soon is a version of Load Tester for 64-bit Windows. Load Tester can run on 64-bit Windows, of course, but it currently runs as a 32-bit process and is subject to the same limitations as if it were running on 32-bit Windows. Testers working … Continue reading »
Tips for Successfully Testing from the Cloud
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 »
Load Tester™ Gives Nacon Consulting a 5x Performance Boost
NACON Consulting, provider of cyber security training solutions for the defense community, was aware of the concurrent user limitations of their online learning management system. In preparation for a major version release for an important client, COO Kent Leonard told his team that he wanted to see an improvement in performance, with documented proof that the system could not only handle the client’s required user load, but exceed it. “In my eighteen years of experience in IT development, I’ve found that testing is typically not as robust as it should be. I wanted to change that and do proper testing,” … Continue reading »
Configuring File Uploads
When a testcase has a file upload in it, Load Tester automatically handles the file upload during replays and load tests. However, in many tests each user should upload different file contents (and possibly use a different file name). Load Tester has streamlined this process to make it very easy to handle. Just follow these easy steps:
1) Gather the set of files to be uploaded
2) Import them into Load Tester (Window > Preferences > Web Performance > File Upload) and generate a dataset
3) Find the file field in the testcase using the Fields View
4) Configure the field to use the … Continue reading »
Load Testing: Software or Services?
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 »
Load Testing Metrics: Comparing to the Median
Once you’ve been using Load Tester for a while, it’s easy to find the minimum, maximum, and average page durations. But how does that compare against the median page duration, or percentiles?
Starting with Load Tester 3.6, these measurements can now be made, but it’s been made easier to find in Load Tester 4.1. First, you will need to enable “Detailed Page Durations”. In Load Tester 4.1, simply make sure the “Detailed Page Durations” option is checked on the “Data Collection” section of the Load Test Configuration editor.
With that setting enabled, just run your Load Test as normal. When examining the … Continue reading »