Instabug Challenge

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INSTALLATION

Make sure you have docker installed on your machine.

    docker-compose up --scale instabug-chat=3

Note: As Ruby on Rails is a fully featured framework, I used a mini framework in GoLang to build the task faster.

USAGE

• Attached is a postman collection that you can use to test the API. in the top level directory of the project

SYSTEM DESIGN

Components:

• NGINX - Reverse proxy server that loads balance requests to the API.
• Go API - Handles requests
• Elasticsearch - Used to index the messages for search functionality.
• MySQL - Main datastore for the application.
• Redis - Used for caching the chats and messages data, it caches the GET list only [for simplicity]
• RabbitMQ - Used for handling the messages creation between the API and the Worker.
• Go Worker - Worker that handles the message creation.
• Event/Listener - Used to handle the message creation event to store indexed data in Elasticsearch.
• Unit Tests - Unit tests for Application service go test ./tests/unit/services/.

API Endpoints:

GET /applications
POST /applications
GET /applications/:Token
PUT /applications/:Token

POST /applications/:Token/chats
GET /applications/:Token/chats
GET /applications/:Token/chats/:ChatNumber

POST /applications/:Token/chats/:ChatNumber/messages
GET /applications/:Token/chats/:ChatNumber/messages
GET /applications/:Token/chats/:ChatNumber/messages/:MessageNumber
PUT /applications/:Token/chats/:ChatNumber/messages/:MessageNumber

Decisions:

• Preventing collisions of chat_number per application and message_number per chat by using Compound Indexes in the database.

• Handling race conditions in getting the chat_number and message_number by using select for update in transactions.

Project Structure:

Note: All system components are put together in the same structure for simplicity.

• api - Go API, you can find the routes, controllers, services, and models.
• worker - Go Worker, you can find the worker that handles the message creation in ./pkg/rabbitmq/message_worker.go
• postman-collection - Postman collection for the API in ./ChatSys.postman_collection.json
• unit-tests - Unit tests for Application service in ./tests/unit/services/