pondělí 23. března 2015
From 4.0 to 4.1
This release has some really cool features that makes PerfCake even easier for usage. Actually there are 26 of enhancements and new features in this release. Just have a look on the list to see if you could make a use of them.
Except for these cool features there is one thing we are especially proud of in this release. This is its stability. We finally managed to get rid of all the raise conditions appearing now and then and bothering us constantly. I do not want to claim that there aren't any now. But there aren't any we are aware of. And there is a fair chance that nobody will discover a new one (until we change the code ;-)).
Unfortunately, bad things happen and there will be version 4.1 soon. Especially due to a bug that prevents smooth shell script usage randomly.
We also decided to fix several other issues. This is mainly because we want to get ready for a possibility to present PerfCake publicly soon again. All information on that will be shared once we have an official confirmation. Stay tuned!
neděle 8. února 2015
DevConf 2015
The first is the ability to automatically generate chart reports using Google Charts. This is provided in the form of a ChartDestination. PerfCake also automatically combines recent results with any previously existing in the output directory which gives you an automatic comparison.
We have demonstrated this with several HTTP Reverse Echo clients, each of which was implemented in a different language. We reused the same scenario to show the user friendliness of PerfCake and the fact that PerfCake does not care about the language the measured application is developed in.
The second major feature was automatic memory leak detection. This works only for Java currently, however, we were able to detect all the leaks.
The way we do presentations is that we try to evolve over time. We try hard to create something new for anybody visiting all of our presentation still have some fun. The thing is that we did not see many people coming back and listening to new things. After this last presentation we are likely to reevaluate our approach and make sure we always presents the basics. If you could provide your opinions on that, we would love to take them into account.
úterý 21. října 2014
How fast can PerfCake be?
For a long time, we were wondering what are the limiting abilities of PerfCake. Mainly, what is the impact of PerfCake itself on the CPU. We created a simple scenario with the DefaultMessageGenerator and DummySender (that does nothing). We did not use validation for now as you can see in the scenario below. The aim of this exercise was to investigate thread management and proper data structures usage in the PerfCake core. On an Intel Xeon (2x 8 core CPU) we achieved over 75 billions of requests per second using 4096 concurrent threads/clients. Is your system that fast?
There is one more parameter to the test - the queue size. This is the size of an internal buffer used to prepare requests. If the queue was too short or too slow, it would block the maximal throughput. You can happily ignore this as the information is mainly for the developers. The colorful lines just make the charts look more joyful ;-)
We also wondered, how PerfCake can perform on a limited device based on an ARM CPU. Could you use your mobile phone as a load generator for example? So we run the same scenario on Cubieboard 2. The numbers are lower and the queue size now plays more important role. For our Fedora 19 installation on the device, there was a limit on the maximum number of threads for a system process. This is why the chart ends around 512 threads.
Following is the scenario.
Technical preview of DSL is in 3.3
As we promised, PerfCake 3.3 is out. The main reason for this release is a feature we originally planned for 3.0. We wanted to present this at GeeCON 2014 in Prague, so here is the first "technical preview". We also fixed some minor bugs - as we found them, there was no reason for postponing the fix. We hope to collect some feedback on the DSL implementation and possibly improve it.
We also look forward to see current and find some new users at GeeCON. Meanwhile, we also presented PerfCake in an IT company and discovered some new feature requests. Therefore, we started speaking about receivers, timers, correlators... You might possibly see some of the revolutionary concepts in release 4.0.
pátek 10. října 2014
PerfCake 3.0 is out, so is 3.1 and 3.2...
You can have a look on the list of closed issues for this release. The user experience should be now better. We prepared automated scenario migration to the last version (running this is however still little bit clumsy), we fixed all the issues with reporting (early or late results were not recorded), we did some PoC with Google charts output (and decided to solve that differently in version 4.0), we have some progress on the tooling (Eclipse plugin is almost done), we extended our tests to the level of advanced integration testing (running in-container testing of JMS sender for instance, special credit goes to an university student who implemented it), and many other changes that might be hardly visible from the outside but were important inside.
There is still one component in PerfCake that is not easy to extend or to implement on your own - the generators. They do not have an interface but an abstract parent class. This is something we would like to change for programmers' convenience.
From the users perspective, our priority is the tooling, documentation, migration from previous versions (and possibly migration from other tools), execution in a clustered environment, ability to directly represent results graphically (using charts).
We also have a plan to finally provide another way to specify the scenario - a DSL language. This feature is almost in a technical preview state.
So, what went wrong during the release and why we ended up with version 3.2? The reason is quite silly and it is a lesson learned for the next release. During the release procedure, we prepare everything on Github first. The master branch has a new version and the devel branch is set to continue on the next release. Then we prepare the artifacts and upload them to Sonatype for them to appear in the public Maven repository. Then our Continuous Integration environment automatically consumes the sources from master and runs all the tests. It also creates downloadable artifacts for automatic web pages refresh.
So after releasing version 3.0, we realized that the tests do not work well in the CI environment. We decided this must be caused by a different environment setup, implemented a fix, executed tests locally and released version 3.1.
But this did not help! Still the same errors appeared in the CI. After a more thorough inspection we realized that there is a problem with the javadoc Maven plugin (the recent version was backward incompatible). So we eventually fixed that and released version 3.2.
Next time, we must run our CI stuff before the upload to Sonatype.
And one more thing - there will be another release, version 3.3, shortly before GeeCON in Prague 2014. We want to present some cool new features there during the Lightning talks.
sobota 21. června 2014
Release 2.1
During midsummer we released hot-fix release v2.1 that fixes one such bug.
We would like to thank everybody who have helped... Thank you very much!
středa 9. dubna 2014
Release 2.0
Some time ago, we celebrated the Spring equinox with the 2nd release of PerfCake. Did we manage to implement everything we wanted? The answer is no again. Does it really matter? Not that much. We mainly focused on fixing some issues that the users were facing. Especially correct reporting of reaching 100% in time controlled runs. We also improved the framework performance so it has minimal influence on the system being measured. So the priorities have changed and we did some things that were not in the plan originally. It is a very nice feeling to see how the product gets matured. Like some good quality whisky...
Since release 1.0, we presented PerfCake to local public and we were surprised by the positive audience feedback. However, there are still questions we are not able to answer at the moment. Or more precisely, we are not able to provide the evidence for our answers. So before the next release, we would like to aim on being the best performance testing framework on the market. Because of that, we plan to publish comparisons with other frameworks and provide migration scenarios.
We learned that nice reporting is important to our users. So we would like to implement a reporter that generates charts.
For links to public talks, see our twitter.



