All of us surely have come across bunch of systems that supports live commenting. For example, facebook live commenting, twitch/youtube live stream commenting, reddit live stream commenting etc. Lets deep dive in the system that support the live commenting feature. Requirements: User should be able to see active real time comments on the post/video/stream across the globe. System should be highly available, fault tolerant. Due to CAP theorem, we will need to trade the consistency. Consider our system to be eventually consistent. If the comment is made, its okay for us if it takes few seconds to appear everywhere else. Goal: to build a system to sync live comments across the demographies & data centers to build a system that supports the real time pushing of comments to the web/mobile clients. Estimation: Consider 100M Daily Active Users (DAU), 400M daily posts/videos/streams on the system and daily 10B comments being made on different streams/videos/posts. To support such high sc
Introduction I have been working on Golang for quite a time now. I explored a lot of features. The few that caught up my eye was 'Scalability' & 'Concurrency'. Scalability & Concurrency have been some of the major objectives behind the design of Golang. Let's dive in a bit. Threads A thread is the unit of execution within a process. A process can have anywhere from just one thread to many threads. On a machine, we have multiple processes running and in these processes, we have independent or dependent threads aggregating computations. Contextually, these threads are further broken down into two types, namely User-Level Threads and Kernel Level Threads . The basic difference between these threads is that the kernel-level threads are managed, operated, and scheduled by the operating system(kernel), and user-level threads are managed, operated, and scheduled by the application layer. Just to have more understanding about them, let's list dow