How to run 4.5 Million tests per day, and why

If you had to guess what software company has the expertise (and plain guts) to scale up the CI (continuous integration) concept to running almost 5 Millions tests per day, what would you say? Google, of course. This short talk by Mark Striebeck (a Google employee) was very interesting and somewhat illustrative of what Google is capable of when it sets its collective mind to something.

People at Google were finding it harder to apply CI because of the large size of their test base. Tests were taking a long time to run so they were run less often. To solve this problem, they decided to leverage the Google infrastructure and implemented their test harness as a scalable web service. The test execution is distributed on more than 1500 CI servers!

The interface to the test system is a nice dynamic web page where you can filter and display the results in many different ways, giving you the exact view you want on your test results. And as you would expect, the search works pretty well, too.