Load Testing Blog
Showing posts tagged “Load Testing”
Load Testing Anti-Patterns: Building the Perfect Test
We run into a wide variety of customers who need load testing software and/or services. While many are working their way through the process on-the-fly, others have toiled long and hard to develop a thorough testing plan, complete with detailed descriptions of exactly how the load test should be performed. On occasion, this testing plan is incredibly specific – detailing exactly how many users should be doing this or doing that, exactly how many users should click a button at the same time, exactly which search result the user … Continue reading »
Knowing your Security with Stress Testing
In the past, we’ve had plenty of discussion on how performance effects user experience, and how that relates to conversions. But, can a server’s performance effect it’s security?
During a previous test, we had a customer whose site included a contact form. The user would complete the contact form in their browser, and the application server would convert this response into an e-mail and send it through a mail server. The contact form, coupled with the use of a CAPTCHA, helps to cut back on undesirable messages. During our testing, we … Continue reading »
Choosing the scenarios for a load test
What to test?
Occasionally, we encounter customers who have only a single scenario to test. For example, one client developed an application in which the only scenario of interest involved a user registering him/herself with the system and scheduling an appointment. When this happens, the tester may devote their efforts to the accurate simulation, testing and analysis of this single scenario. You are unlikely to be so lucky.
In any moderately complex system, there are dozens or even hundreds of scenarios that are candidates for load testing. You are not likely … Continue reading »
Testing tip: Make it Fail
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 … 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 … 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 … Continue reading »
Keeping Your Load Testing Cases Current (How To)
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 … Continue reading »
What is “Web Bandwidth” and how do you test it?
When diagnosing performance problems with our clients websites, it is not uncommon for the bandwidth to come into question. Very often, the bandwidth chart will show a distinct plateau and it can be difficult to determine if this is cause or effect. This example shows outgoing server bandwidth (green) as the users (blue) ramp up. It could be interpreted as a bandwidth limitation around 8Mbps. In this case it is not – the limitation is elsewhere in the system.
It can be challenging to prove that bandwidth … Continue reading »
Is your Load Balancer increasing your Bandwidth usage?
Is your load balanced website using more bandwidth under load than a single server would? In a previous article (“Status code 200 didn’t match expected: 304”), we discussed how a website may return full data content back to a client, even when the browser had the resource cached. If you believed that adding an extra server and a load balancer will increase your performance, this can be an unsettling surprise. The problem arises when two web servers are delivering different Entity Tags for the same static resource:
In … Continue reading »
For Bell Canada, Early Performance Testing Spells Success
When Bell Canada began development of an important new customer-facing application, project lead Mr. Roger Bejjani knew he needed to find a web testing tool that would help fine-tune performance throughout the development process and into production. Having used Empirix (purchased by Oracle) and Load Runner (purchased by HP)in the past, he decided to forgo overpriced software and look for a tool that would give him the functionality he needed at a more reasonable price. The main requirement would be load testing HTTP and HTTPS requests, and the … Continue reading »
