Mini Twitter

A Twitter like application where user can tweet and have followers

Mini-Twitter Server API

Mini-Twitter Consumer API

Archetecture

Requirements

Functional Requirement

System shall provide capability for

• user to follow other user
• user to create tweet
• user to login to the system
• user to signup at the system
• user to see most recent 100 tweets from people they follow after login

Non-functional Requirements

• Our service needs to be highly available.
• Acceptable latency of the system is 200ms for timeline generation.
• Consistency can take a hit (in the interest of availability); if a user doesn’t see a tweet for a while, it should be fine.

Capacity Estimation and Constraints

Given:

• 10K total user, each person tweets 10 message a day
• new tweets/day: 100k tweet a day

Assumption:

• each user follow 200 people, DAU: 10K

Calculation

total tweet-views estimate : 2M/day

• assume on average a user visits their timeline two times a day. On each page if a user sees 100 tweets.
• 10K DAU * (2 * 100)=>2000k =2M/day

storage estimate : 31 MB/day

• Assume each tweet has 140 characters and we need two bytes to store a character without compression.
• Assume we need 30 bytes to store metadata with each tweet
• Total storage we would need: 31 MB/day
• 100k * (280 + 30) bytes => 31000 KB/day = 31 MB/day

bandwidth estimate: 0.32KB/s

• 100k tweet a day * 280 bytes per tweet / 86400 second = 0.32KB/s

Technology Choice

• Server
  • Springboot, webmvc, spring security
• Consumer (calling application)
  • Springboot rest template
• Infrastructure
  • AWS EC2, RDS, S3, loadbalancer security group, autoscale group
• Deployment
  • Maven, AWS elasticbeanstalk
• Testing
  • Mockito, Springboot test
• UI
  • swagger

System API

Mini-Twitter Consumer API

Mini-Twitter Server API

Scale to 10k user