Hello Git user. In this blog post I will discuss a technique for a unique version calculation for every Git commit. You may ask why we need this, after all every commit in Git is identified by a unique sha1 hash. That’s right, let’s take 2 commits, 4bd92c9 and f5fc029, use their sha1 hash as a version and perform a simple A/B test. The test showed that 4bd92c9 is preferred to f5fc029. If this is the case, how can we tell: Which version is newer? If 4bd92c9 is included in f5fc029, or vice versa? What branch they were built from? It seems we need an alternative. The common standard for the versioning is a SemVer scheme. We will use its parts as follows: Major – manual increment Minor – every released feature will increment the minor Patch – will always be 0 Now let’s take a look at our […]
The existing CI processes in Taboola are quite demanding – a full product build includes 150 maven modules accounting for about 20000 unit tests. Beside running builds from master branch there are also builds for all feature branches and patch releases. All in all accumulating to more than a hundred builds per day. Some of the executed tests are pretty heavy on CPU and memory, performing resource-intensive data crunching. As you can imagine – all this requires substantial CI infra horse power. Which it definitely possesses: Taboola’s Jenkins cluster currently has 35+ Jenkins slaves, each with 20 to 40 CPU cores and at least 100 Gb memory. Each slave runs 5 to 10 executors. All in all – a powerful CI/CD factory. But even with all this power – there are limitations. On the day of the weekly release the volume of builds peaks and we sometimes find ourselves starving […]
Synthetic monitoring is something that we all do. It’s almost something that you don’t think about. You set up a monitor and it just tells you if the service is up or down, most times with just a simple GET. There are the giants in this field (lately consolidated under the Keynote brand as part of AppDynamics) and the new comers like Catchpoint, ThousandEyes, Pingdom (now part of SolarWinds) and WorldPing. All solutions have the same basic concept, pull website information from different agents around the world and provide visibility for the web site operator on uptime, response times and other metrics. But what happens with you have a failure, and no alert? These tools have become so widespread and have such long usage history, that it almost seems pointless to compare. This is a solved problem, no? Just take the cheapest one out there and you’re done. Here at […]