Задание №3

Цели выполнения задания

• Попрактиковаться в настройке мониторинга
• Попрактиковаться в поиске возможностей для оптимизации
• Попрактиковаться в проверке гипотез и обосновании предложений по оптимизации
• Познакомиться с интересным живым open-source проектом

Подготовка

• Завести dev.to локально
• Настроить свой Skylight для мониторинга локального dev.to
• Настроить свой NewRelic для мониторинга локального dev.to
• Настроить свой Scout для мониторинга локального dev.to
• Настроить свой Prometheus + Grafana для мониторинга локального dev.to

Оптимизация

Все инструменты мониторинга показывают, что самой горячей точкой является главная страница, StoriesController#index.

В частности, заметное время занимает рендеринг partial-ов _single_story.html.erb.

Рассмотрите гипотезу о том, что можно закешировать <%= render "articles/single_story", story: story %> в _main_stories_feed.html.erb и это даст заметный эффект.

• Не забудьте включить локальное кэширование (touch tmp/caching-dev.txt)
• Нагрузите главную страницу запросами, так чтобы они отразились в системах мониторинга
• Сделайте benchmark с помощью ab
• Сделайте оптимизацию
• Снова нагрузите страницу запросами и перезапустите benchmark

Если вы посчитаете, что применить кэширование здесь целесообразно, оформите обоснованный PR с этим предложением. Напишите в описании PR, какая была гипотеза, откуда она взялась, как вы проверяли гипотезу, какие результаты получили. Приложите скриншоты графиков мониторинга, если на них виден эффект оптимизации.

Bonus №1

Обратите внимание на класс FlareTag. Он фигурирует в отчётах систем мониторинга как часто вызываемый код приложения. Можно ли оптимизировать что-то в этом классе, или в методах, которые он использует?

Если вы придумаете как его оптимизировать, попробуйте сделать обоснованный PR, как в основной части задания.

Bonus №2

Добейтесь запуска приложения в режиме RAILS_ENV=production.

Можно просто начать, и далее устранять возникающие проблемы одну за одной.

Если получится запустить приложение в production режиме, сравните метрики с режимом development. Сравните отчёты Rack-mini-profiler с development.

Сделайте возможность удобно запустить local-production, добавьте информацию об этой возможности в Readme.

Bonus №3

Поищите возможности для оптимизации самостоятельно. Если найдёте, добавляйте в PR ваши оптимизации с обоснованиями.

Сдача задания

PR в этот репозиторий с кодом и подробным описанием проделанной работы в описании PR-а.

DEV Community 👩‍💻👨‍💻

The Human Layer of the Stack

Welcome to the dev.to codebase. We are so excited to have you. With your help, we can build out DEV to be more stable and better serve our community.

What is dev.to?

dev.to (or just DEV) is a platform where software developers write articles, take part in discussions, and build their professional profiles. We value supportive and constructive dialogue in the pursuit of great code and career growth for all members. The ecosystem spans from beginner to advanced developers, and all are welcome to find their place within our community. ❤️

Table of Contents

• Contributing
• Codebase
  • The stack
  • Engineering standards
    • Style guide
    • Husky hooks
• Getting Started
  • Prerequisites
  • Standard Installation
  • Docker Installation (BETA)
  • Starting the application
  • Suggested Workflow
• Additional docs
• Product Roadmap
• Core Team Members
• License

Contributing

We encourage you to contribute to dev.to! Please check out the Contributing to dev.to guide for guidelines about how to proceed.

We expect contributors to abide by our underlying code of conduct. All conversations and discussions on GitHub (issues, pull requests) and across dev.to must be respectful and harassment-free.

Where to contribute

All issues labeled with approved are up for grabs. For clarification on how we label issues, check out their definitions here.

When in doubt, ask a core team member! You can mention us in any issues or ask on the DEV Contributor thread. Any issue with the good first issue tag is typically a good place to start for anyone new to the project. For newer developers, try 'entry-level' issues.

Refactoring code, e.g. improving the code without modifying the behavior is an area that can probably be done based on intuition and may not require much communication to be merged.

Fixing bugs may also not require a lot of communication, but the more the better. Please surround bug fixes with ample tests. Bugs are magnets for other bugs. Write tests near bugs!

Building features is the area which will require the most communication and/or negotiation. Every feature is subjective and open for debate. The product roadmap should be a good guide to follow. As always, when in doubt, ask!

How to contribute

1. Fork the project & clone locally. Follow the initial setup here.
2. Create a branch, naming it either a feature or bug: git checkout -b feature/that-new-feature or bug/fixing-that-bug
3. Code and commit your changes. Bonus points if you write a good commit message: git commit -m 'Add some feature'
4. Push to the branch: git push origin feature/that-new-feature
5. Create a pull request for your branch 🎉

Note: be sure to maintain your fork!

Contribution guideline

Create an issue

Nobody's perfect. Something doesn't work? Or could be done better? Let us know by creating an issue.

PS: a clear and detailed issue gets lots of love, all you have to do is follow the issue template!

Clean code with tests

Some existing code may be poorly written or untested, so we must have more scrutiny going forward. We test with rspec, let us know if you have any questions about this!

Create a pull request

• Try to keep the pull requests small. A pull request should try its very best to address only a single concern.
• Make sure all tests pass and add additional tests for the code you submit. More info here
• Document your reasoning behind the changes. Explain why you wrote the code in the way you did. The code should explain what it does.
• If there's an existing issue related to the pull request, reference to it by adding something like References/Closes/Fixes/Resolves #305, where 305 is the issue number. More info here
• If you follow the pull request template, you can't go wrong.

Please note: all commits in a pull request will be squashed when merged, but when your PR is approved and passes our CI, it will be live on production!

How to get help

Whether you are stuck with feature implementation, first-time setup, or you just want to tell us something could be done better, check out our OSS thread or create an issue. You can also mention any core team member in an issue and we'll respond as soon as possible.

👉 OSS Help/Discussion Thread 👈

The bottom line

We are all humans trying to work together to improve the community. Always be kind and appreciate the need for tradeoffs. ❤️

Codebase

The stack

We run on a Rails backend with mostly vanilla JavaScript on the front end, and some Preact sprinkled in. One of our goals is to move to mostly Preact for our front end.

Additional technologies and services are listed on our docs.

Engineering standards

Style Guide

This project follows thoughtbot's Ruby Style Guide, using Rubocop along with Rubocop-Rspec as the code analyzer. If you have Rubocop installed with your text editor of choice, you should be up and running.

For Javascript, we follow Airbnb's JS Style Guide, using ESLint and prettier. If you have ESLint installed with your text editor of choice, you should be up and running.

Husky hooks

When commits are made, a git precommit hook runs via husky and lint-staged. ESLint, prettier, and Rubocop will run on your code before it's committed. If there are linting errors that can't be automatically fixed, the commit will not happen. You will need to fix the issue manually then attempt to commit again.

Note: if you've already installed the husky package at least once (used for precommit npm script), you will need to run yarn --force or npm install --no-cache. For some reason, the post-install script of husky does not run when the package is pulled from yarn or npm's cache. This is not husky specific, but rather a cached package issue.

Getting Started

This section provides a high-level requirement & quick start guide. For detailed installations, please check out our docs.

Prerequisites

• Ruby: we recommend using rbenv to install the Ruby version listed on the badge.
• Yarn: please refer to their installation guide.
• PostgreSQL 9.4 or higher.

Standard Installation

0. Make sure all the prerequisites are installed.
1. Fork dev.to repository, ie. https://github.com/thepracticaldev/dev.to/fork
2. Clone your forked repository, ie. git clone https://github.com/<your-username>/dev.to.git
3. gem install foreman
4. Setup your database
   • Create config/database.yml by copying from the provided template (i.e. cp config/database.yml.sample config/database.yml)
   • Update the config/database.yml file if needed.
5. Set up your environment variables/secrets
   • Take a look at Envfile. This file lists all the ENV variables we use and provides a fake default for any missing keys. You'll need to get your own free Algolia credentials to get your development environment running.
   • This guide will show you how to get free API keys for additional services that may be required to run certain parts of the app.
   • For any key that you wish to enter/replace:
     1. Create config/application.yml by copying from the provided template (ie. with bash: cp config/sample_application.yml config/application.yml). This is a personal file that is ignored in git.
     2. Obtain the development variable and apply the key you wish to enter/replace. ie:

     GITHUB_KEY: "SOME_REAL_SECURE_KEY_HERE"
     GITHUB_SECRET: "ANOTHER_REAL_SECURE_KEY_HERE"
     

   • If you are missing ENV variables on bootup, envied gem will alert you with messages similar to 'error_on_missing_variables!': The following environment variables should be set: A_MISSING_KEY..
   • You do not need "real" keys for basic development. Some features require certain keys, so you may be able to add them as you go.
6. Run bin/setup
7. That's it! Run bin/startup to start the application and head to http://localhost:3000/

View Full Installation Documentation

Docker Installation (BETA)

Our docker implementation is incomplete and may not work smoothly. Please kindly report any issues and any contribution is welcomed!

1. Install docker and docker-compose
2. git clone git@github.com:thepracticaldev/dev.to.git
3. Set environment variables above as described in the "Basic Installation"
4. run docker-compose build
5. run docker-compose run web rails db:setup
6. run docker-compose run web yarn install
7. run docker-compose up
8. That's it! Navigate to localhost:3000

Starting the application

We're mostly a Rails app, with a bit of Webpack sprinkled in. For most cases, simply running bin/rails server will do. If you're working with Webpack though, you'll need to run the following:

• Run bin/startup to start the server, Webpack, and our job runner delayed_job. bin/startup runs foreman start -f Procfile.dev under the hood.
• alias start="bin/startup" makes this even faster. 😊
• If you're using pry for debugging in Rails, note that using foreman and pry together works, but it's not as clean as bin/rails server.

Here are some singleton commands you may need, usually in a separate instance/tab of your shell.

• Running the job server (if using bin/rails server) -- this is mostly for notifications and emails: bin/rails jobs:work
• Clearing jobs (in case you don't want to wait for the backlog of jobs): bin/rails jobs:clear

Current gotchas: potential environment issues with external services need to be worked out.

Suggested Workflow

We use Spring and it is already included in the project.

1. Use the provided bin stubs to automatically start Spring, i.e. bin/rails server, bin/rspec spec/models/, bin/rake db:migrate.
2. If Spring isn't picking up on new changes, use spring stop. For example, Spring should always be restarted if there's a change in environment key.
3. Check Spring's status whenever with spring status.

Caveat: bin/rspec is not equipped with Spring because it affects Simplecov's result. Instead use bin/spring rspec.

Additional docs

Check out our dedicated docs page for more technical documentation.

Product Roadmap

Our new product roadmap can be found here. Many notes need to be converted to issues but this should provide an overview of features we plan to work on, as well as features we are considering.

Core team members will move issues along the project board as they progress.

• Ideas & Requests: features up for discussion.
• Needs Owners: features in need of an owner.
• Committed: features we're committed to building -- free for contributors to work on, but please communicate with the owner beforehand.
• In Progress (early stage): work has begun on feature.
• In Progress (late stage): feature is near completion.

Core team

• @benhalpern
• @jessleenyc
• @peterkimfrank
• @maestromac
• @zhao-andy
• @aspittel

License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. Please see the LICENSE file in our repository for the full text.

Like many open source projects, we require that contributors provide us with a Contributor License Agreement (CLA). By submitting code to the DEV project, you are granting us a right to use that code under the terms of the CLA.

Our version of the CLA was adapted from the Microsoft Contributor License Agreement, which they generously made available to the public domain under Creative Commons CC0 1.0 Universal.

Any questions, please refer to our license FAQ doc or email yo@dev.to

Happy Coding ❤️