This article is a summary explanation of a paper from WeChat published in SoCC 2018.
I’m not going to put the abstract here, you can easily find it in the paper, but the overall idea of the paper is to show how WeChat managed to solve the problem of overload control, and they presented DAGOR, the system they developed and they are using in production to solve this problem.
I’m just going to leave here a quote from the paper on what kind of scaling we are talking about.
WeChat’s microservice system accommodates more than 3000 services running on over 20,000 machines in the WeChat business system, and these numbers keep increasing as WeChat is becoming immensely popular… As WeChat is ever actively evolving, its microservice system has been undergoing fast iteration of service updates. For instance, from March to May in 2018, WeChat’s microservice system experienced almost a thousand changes per day on average.