System design: facebook chat

August 7, 2017

Introduction

It is very good learning experience to do system design practice. Today  I chose to study the topic: How to design a facebook chat.

Design Talk

Plan to read system design website 30 minutes a time. Link is here on github in English.

Plan to read system design article on palantir. The link is here.

Harvard lecture video about website system design: the link is here. 

Lecture notes is here. 

First, go over the transcript found on one website mixed in Chinese:

Here is the link.

Here is the link about basic questions about spec and requirements.

Step1: 先問所有requirement, spec 這個系統需要提供什麼功能

Step2: Constrains: 問他我們需要處理多少traffic, 多少data, latency重不重要 A和C選哪個

Step3: 計算需要多少機器 要用什麼storage

Step4: Abstract design: 先畫出大架構！ 每個會出現的component都要畫出來 再看面試官希望你深入講哪個component

Step5: Scale: 讓你的system有fault tolerance, scale成大公司的系統架構