Load Impact 2.0 was released at the end of October (27th). The first few days after release were pretty chaotic, with lots of minor issues and some major ones, but having been involved in many big releases during my career I have to say that this one went pretty well actually. The system was up and functional most of the time, the first few days post-release, and that isn’t bad at all 🙂
Still, there were some difficulties, of course. We had problems first with AMEX payments due to contractual reasons (AMEX payments have been removed for now, until we manage to get through the AMEX bureaucracy) and then with VISA/MC payments. Then there was occasional problems with internal queueing systems that caused some load tests to either fail, “freeze” (get stuck in some state), or never get started. All these issues should have been resolved by now, but there are likely smaller things that will pop up from time to time, so we urge everyone to get in touch with us if you see anything strange happening on the site. Don’t hesitate to get in touch with us even if you’re unsure whether something is a problem on our side or not, we want to know about all situations where someone has any kind of problem using our service. No issue is too small.
In general, the system is starting to get very stable now, however, and we see more activity than before the release, with more user registrations and more tests being executed. We also see more advanced usage of our service – more people are writing advanced load scripts and running both larger and more complex load tests than ever before. It is all very encouraging and tells us that we are moving in the right direction!
So what is so great about 2.0 then?
Some people may see Load Impact 2.0 as simply an upgrade, but it’s more like the launch of a whole new service. It is that much different from 1.0. We have kept some 1.0 key elements that we (and hopefully everyone else) liked such as the ability to run small, simple tests anonymously from our front page, the ability to watch other such anonymous tests that are being run, and the scripting language and scripting API, but behind the scenes most of the code base is new and 2.0 includes a lot of new functionality that didn’t exist in 1.0. Here is a small list:
- Large-scale load tests
As we are now using public cloud infrastructure (Amazon) to generate load test traffic, we have the ability to scale up a load test to a very large size at any of the geographic locations where there are cloud servers available (currently California, Oregon and Virginia in the US, plus Ireland, Japan and Singapore outside the US). - Multiple user scenarios in a single test
In 2.0 we introduce “user scenarios”. A user scenario defines a certain simulated user category and what that category should be doing on your site. An example can be an e-shopping site that has two types of visitors – one type that just browses the site without buying anything, and another type that registers a user account on the site and then goes on to actually buy products on the site. In Load Impact 1.0 you could not easily combine these two different user categories in a single load test, but with Load Impact 2.0 it is easy – you just create two different user scenarios, that run different load scripts, then you configure your load test to use these two scenarios. - Multiple geographical traffic sources
With Load Impact 2.0 you can now choose to have your traffic originate from more than one physical place, if you want. You can specify any number of combinations of user scenarios (described above) and geographical locations where that particular user scenario should be executed, and create very complex load test configurations where you define that e.g. 10% of the total number of simulated users during the load test should run user scenario X from geographical location Y. - More performance metrics
We now collect more performance metrics than in 1.0, such as “requests per second”, and we collect many more sampling points that are all time-based rather than client level-based. This results in more performance data available at higher resolutions than before. - Much more advanced chart/graph capabilities
We provide a very dynamic test report page where you can create your own charts and graphs, plotting a wide range of parameters and correlate data with a certain user scenario or test results from a certain geographical region. - Text-based script editor
For expert users, a text-based scripting editor is usually the best choice, and in Load Impact 2.0 we provide the option to choose between our graphical script editor (LILE) and a text editor that allows easy copy-and-paste and faster code entry for the experienced programmer. Load script programmers now have much more choice in how they create their load scripts. - Continuous tests
Load tests are now executed continuously, which means that a simulated client thread is never shut down as long as the load level is meant to increase. Old simulated clients will just continue execution, reiterating their load script again and again, while more clients are being added. The result is a smoother and more time-efficient ramp-up process than was offered in Load Impact 1.0. - Credit based pricing model
Load Impact 2.0 introuces the credit based model that means there is no difference between one user and the next as regarding them being a “premium” user or not. All users are the same, they just have different amounts of credits, and the ones that have more credits can run larger and longer tests than those who have few credits. This provides several advantages – first of all it allows us to skip all the old limits on how many tests you can run per 24 hours, etc. Now, every test you run consumes credits and only the number of credits you have affects the number of tests you can run. Secondly it means we don’t have to restrict access to some functionality to premium users – everyone can do everything on the system, so it is easy to “try before you buy”. Thirdly, it makes our product much simpler in general as we only sell one single thing now – Credits – while as earlier we sold access to different premium levels for different amounts of time, making everything a lot more complex. The drawback, however, is that it can be difficult for people to understand exactly how many credits they need to do the testing they want to do. All in all, though, we think the upsides with the credit model are much bigger than the downsides.
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