Retrospective

As it should be able to process 10M requests per day it means 115 request per second, a current solution on free Heroku supports: - 208 http requests per second - 125 jobs per second

• What went well?

  • Tests with rspec helped to avoid regression
  • Counter caches helped to denormalize a database
  • React-bootstrap helps to make UI changes quickly
  • Redis cache improves a response time for statistics endpoints
  • Sidekiq works faster than Resque. 10_000 jobs was proceeded by Resque for 3m39s, by Sidekiq 0:30s

• What didn’t go well?

  • Using indexes on string fields like url can slow down inserts in future
  • Using counter_caches requires an additional update queries
  • UI should have a unit and integration tests as well
  • free Heroku database has a limit for rows ~ 1M, impossible to make good stress-testing with an emulation of a one month working for example

• If I had more time to work on this,

  • Stress-testing
  • Investigate a possibility to move analytics data to another storage
  • Write tests for UI
  • Make a documentation more detailed
  • Choose pure Rack instead of Sinatra
  • Choose pure css instead of Bootstrap

Deployment

Automatic deploys to Heroku from master are enabled

Link to the app on Heroku: https://bytelyapp.herokuapp.com

Development

Setup a development environment

Change database settings config/database.yml

Run setup script bundle exec rake setup

Run a web app bundle exec puma -C config/puma.rb

Run workers bundle exec sidekiq -r ./config/boot.rb -C ./config/sidekiq.yml

Web App

Run in separate windows

bundle exec puma -C config/puma.rb

bundle exec rake ui:start

Web App will be available at http://localhost:3000/ by default

Backend will be available at http://localhost:8080/ by default

Background workers

Run workers bundle exec sidekiq -r ./config/boot.rb -C ./config/sidekiq.yml

Web UI is available at http://localhost:8080/sidekiq/ be default

Console

Useful console like Rails Console

rake console or rake c

Database

Config location

config/database.yml

Create migration

rake db:create_migration NAME=migration_name

Apply migration

rake db:migrate

Rollback migration

rake db:rollback

Tests

Prepare database for tests

rake db:test:prepare

Run tests

rspec

UI

This command produces static files into /public folder

rake ui:build

Start UI in dev mode with hot reloading

rake ui:start

Add a new package using yarn

rake ui:add package-name

Run yarn install rake ui:install