A highly scalable API server that can withstand over 10 million users. This API server is an SNS like Twitter. The following functions are implemented.
- Post a tweet
- Post a comment on tweet
- Follow a user
- Show tweets of followees on the timeline
ER Diagram is following.
Details are written in this article.
- Docker
- Node 16.14
- Express 4.17.3
- DynamoDB 2012-08-10
The following command starts the server and database.
docker-compose up
This project is designed based on DDD(Domain Driven Development).
| Directory Name | DDD Layer | Components |
|---|---|---|
| src/domain | Domain Layer | Entity / Value Object / Repository Interface |
| src/application | Application Layer | Application Service / Serializer |
| src/infrastructure | Infrastructure Layer | Repository / AWS Config |
| src/presentation | Presentation Layer | API Server |
The design of the table and index is as follows.
The use cases and query conditions are as follows.
| Entity | UseCase | Parameters | Table / Index | Key Condition |
|---|---|---|---|---|
| Tweet | getTimelineByUserId | { UserId } | Primary Key | GetItem (ID=UserId AND begins_with(DataType, timeline)) |
| User | getUserByUserName | {Username} | GSI-1 | Query (DataValue=Username AND DataType=usserProfile) |
| Follow | getFolloweesByUserId | {UserId} | Primary key | Query (ID=userId AND begins_with(DataType, followee) |
| Follow | getFollowersByUserId | {UserId} | Primary Key | Query (ID=userId AND begins_with(DataType, follower) |
| Follow | getCountFoloweeByUserId | {UserId} | Primary Key | Select COUNT / Query (ID=userId AND begins_with(DataType, followee) |
| Follow | getcountFollowerByUsreId | {UserId} | Primary Key | Select COUNT / Query (ID=userId AND begins_with(DataType, follower) |
| Tweet | getTweetsByUserId | {UserId} | Primary Key | Query(ID=userId AND begins_with(DataType, tweet) |
| Tweet | getTweetByTweetId | {TweetId} | GSI-1 | Query(DataValue=tweetId AND begins_with(DataType, tweet) |
| Comment | getCommentsByTweetId | {TweetId} | GSI-1 | Query(DataValue=tweetId AND begins_with(DataType, comment) |