The callenge is chat system that has multiple Application identified by token, each Application has many chats identified by a number ( number should start from 1) , each Chat has many messages identified by a number ( number should start from 1) the endpoints should be RESTful
- Using MySQL as datastore
- Using ElasticSearch for searching through messages of a specific chat
- Using Docker to contatinerize the application
- Using RabbitMQ
- Using Redis
- Using RoR
just one command and everything up and running
docker-compose up
i had some issues due to permissions on the containers so please contact me if any of the containers can't be run
| Controller | Verb | URI | body | Description |
|---|---|---|---|---|
| Application | get | /applications/:app_token | no body | get spacific application by token |
| Application | post | /applications | { "name": "name of the application "} | create new application |
| Application | patch | /applications/:app_token | { "name": "updated name of the application "} | update application name |
| Application | get | /applications/:app_token/chats | no body | get application chats |
| Chat | get | /chats/:number | no body | get spacifice chat by number |
| Chat | post | /chats | { "name": "name of the chat ","app_token": "application token "} | create new chat with application token |
| chat | patch | /chats/:number | { "name": "updated name of the chat " ,"app_token": "application token "} | update chat name |
| chat | get | /chats/:app_token/:number/messages | no body | get chat messages |
| message | get | /messages/:app_token/:chat_number/:number | no body | get message by application token and chat number and message number |
| message | post | /messages / {"body":"first_message","chat_number":"1","app_token":"application token"} | create new message | |
| message | patch | /messages/:number / {"body":"first_message","chat_number":"1","app_token":"application token"} | update body of message | |
| message | get | /chats/:app_token/:chat_number/search/:q | no body | search on messges bodies on spacific chat on spacific application |
- On this challenge first i create the schema of the database and add services one by one
- Create all database schema
- Create endpoints
- Add and fetch directly to database to test my schema and endpoints
- Adding redis service to get chat numbers and message numbers from it as a centralized service
- Adding rebbitMQ service to asyncly push created messages and chats to it and add two workers to consume from queues
- I make the queue message acknowledgment to be consistant as possible
- Make the queue durable and publish messages as persistent to save it on the disk
- Consume it by workers with prefetch 1 to consume message one by one due to overload on the workers
- Make sneakers log object log on the same file with Rails file
- Make worker log on sneakers.log file to track issues and problems
- in this phase i had some issues:
- I had to decide which i will requeue the failure message or reject it and push it to retry queue
- I decide to push it to reject it just for not going into infinite loop
- I had to decide also how many number of worker will work
- For now i make the number of workers 2 for each queue because it depend on ROR-application
- Cron job to update the chats count and message count every 45 minutes
- Use Elasticsearch to search for messages in spacific chat
- Optimize Database queries with creating proper indices on database schema
- whenever: this gem allow me to create cron job to update messages_count and chats_count column on chats and applications tables every 45 minutes
- bunny: with bunny i can push to RabbitMQ queue
- sneakers: worker can't consume without this greate gem so i use it to create two workers one for chats creation and other for message creation
- elasticsearch-model: to connect and search on elasticsearch and create index without any issue