jabbink

AH API

Always use User-Agent: Appie/8.22.3 and Content-Type: application/json
Technically there is more information about your device and user ID after it, but the server does not seem to care

Token

If you have a valid access_token, add it as a header in request
Authorization: Bearer access_token

ProGM

Arel Cheatsheet on Steroids

A (more) complete cheatsheet for Arel, including NamedFunction functions, raw SQL and window functions.

Tables

posts = Arel::Table.new(:posts)
posts = Post.arel_table # ActiveRecord

Table alias

giannisp

After automatically updating Postgres to 10.0 via Homebrew, the pg_ctl start command didn't work.
The error was "The data directory was initialized by PostgreSQL version 9.6, which is not compatible with this version 10.0."

Database files have to be updated before starting the server, here are the steps that had to be followed:

# need to have both 9.6.x and latest 10.0 installed, and keep 10.0 as default
brew unlink postgresql
brew install postgresql@9.6
brew unlink postgresql@9.6
brew link postgresql

duffn

DROP TABLE if exists d_date;

CREATE TABLE d_date
(
  date_dim_id              INT NOT NULL,
  date_actual              DATE NOT NULL,
  epoch                    BIGINT NOT NULL,
  day_suffix               VARCHAR(4) NOT NULL,
  day_name                 VARCHAR(9) NOT NULL,
  day_of_week              INT NOT NULL,

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"]

straydogstudio

require 'abstract_controller'
require 'action_controller'
require 'action_view'
require 'active_record'

# require any helpers
require './app/helpers/application_helper'

# active record only if data is here
require './app/models/widget'

djo

# Symlink the shared protected folder
run "ln -nfs #{shared_path}/protected #{latest_release}/protected"

ochronus

# install sysbench
$ apt-get install sysbench

# CPU benchmark, 1 thread
$ sysbench --test=cpu --cpu-max-prime=20000 run

# CPU benchmark, 64 threads
$ sysbench --test=cpu --cpu-max-prime=20000 --num-threads=64 run

# Disk benchmark, random read. See .fio files in this gist

romansklenar

# db/migrate/20131118172653_create_transactional_items_view.rb
class CreateTransactionalItemsView < ActiveRecord::Migration
  def up
    select_sql = File.open("#{Rails.root}/db/migrate/20131118172653_create_transactional_items_view.sql", 'r') { |f| f.read } 
    
    # for materialized view:
    view_sql = "CREATE MATERIALIZED VIEW transactional_items AS (#{select_sql})"
    # for normal view:
    view_sql = "CREATE VIEW transactional_items AS (#{select_sql})"
    

robmiller

#
# Working with branches
#

# Get the current branch name (not so useful in itself, but used in
# other aliases)
branch-name = "!git rev-parse --abbrev-ref HEAD"
# Push the current branch to the remote "origin", and set it to track
# the upstream branch
publish = "!git push -u origin $(git branch-name)"