baweaver

Card = Struct.new(:suit, :rank) do
  include Comparable

  def precedence()      = [SUITS_SCORES[self.suit], RANKS_SCORES[self.rank]]
  def rank_precedence() = RANKS_SCORES[self.rank]
  def suit_precedence() = SUITS_SCORES[self.rank]

  def <=>(other) = self.precedence <=> other.precedence

  def to_s() = "#{self.suit}#{self.rank}"

robhrt7

This is a fork of original gist https://gist.github.com/nrollr/3f57fc15ded7dddddcc4e82fe137b58e, with slight changes on pointing to 5.7 version branch, instead of 8 (latest default of MySQL in Hombrew).

Install MySQL 5.7 on macOS

This procedure explains how to install MySQL using Homebrew on macOS (Sierra 10.12 and up)

Install Homebrew

• Installing Homebrew is effortless, open Terminal and enter :
  $ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
• Note: Homebrew will download and install Command Line Tools for Xcode 8.0 as part of the installation process.

SamSaffron

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'
  gem 'pg'
  gem 'activerecord', '5.2.0'
  gem 'memory_profiler'
  gem 'benchmark-ips'
end

skosch

{
  "__inputs": [
    {
      "name": "DS_PROMETHEUS",
      "label": "Prometheus",
      "description": "",
      "type": "datasource",
      "pluginId": "prometheus",
      "pluginName": "Prometheus"
    }

andriisoldatenko

Latency Comparison Numbers
--------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

cecilemuller

How to setup Let's Encrypt for Nginx on Ubuntu 18.04 (including IPv6, HTTP/2 and A+ SLL rating)

---

Virtual hosts

Let's say you want to host domains first.com and second.com.

Create folders for their files:

moklett

# This demonstrates that, when using async/await, a crash in the task will crash the caller
defmodule Tasker do
  def good(message) do
    IO.puts message
  end

  def bad(message) do
    IO.puts message
    raise "I'm BAD!"
  end

henrik

defmodule HttpRequester do
  use GenServer

  def start_link(_) do
    GenServer.start_link(__MODULE__, nil, [])
  end

  def fetch(server, url) do
    # Don't use cast: http://blog.elixirsips.com/2014/07/16/errata-dont-use-cast-in-a-poolboy-transaction/
    timeout_ms = 10_000

kevcha

When writing a rails app, we often have to deal with multiple namespaces. The most common case is having classic actions and some others in an admin namespace. Some actions may have same views between namespaces.

For exemple, you could have a ProjectsController with an action index :

class ProjectsController < ApplicationController
  def index
    # do something
  end
end

krasnoukhov

My largest Sidekiq application had a memory leak and I was able to find and fix it in just few hours spent on analyzing Ruby's heap. In this post I'll show my profiling setup.

As you might know Ruby 2.1 introduced a few great changes to ObjectSpace, so now it's much easier to find a line of code that is allocating too many objects. Here is great post explaining how it's working.

I was too lazy to set up some seeding and run it locally, so I checked that test suite passes when profiling is enabled and pushed debugging to production. Production environment also suited me better since my jobs data can't be fully random generated.

So, in order to profile your worker, add this to your Sidekiq configuration:

if ENV["PROFILE"]