Dmitriy rda1902

Pry Cheat Sheet

Youtube Tutorial 2013

Command Line

pry -r ./config/app_init_file.rb - load your app into a pry session (look at the file loaded by config.ru)
pry -r ./config/environment.rb - load your rails into a pry session

Debugger

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"]

Finding a Ruby memory leak using a time analysis

When developing a program in Ruby, you may sometimes encounter a memory leak. For a while now, Ruby has a facility to gather information about what objects are laying around: ObjectSpace.

There are several approaches one can take to debug a leak. This discusses a time-based approach, where a full memory dump is generated every, say, 5 minutes, during a time that the memory leak is showing up. Afterwards, one can look at all the objects, and find out which ones are staying around, causing the

YARD CHEATSHEET http://yardoc.org

May 2020 - updated fork: https://gist.github.com/phansch/db18a595d2f5f1ef16646af72fe1fb0e

cribbed from http://pastebin.com/xgzeAmBn

Templates to remind you of the options and formatting for the different types of objects you might want to document using YARD.

Modules

Improved YARD CHEATSHEET http://yardoc.org

forked from https://gist.github.com/chetan/1827484 which is from early 2012 and contains outdated information.

Templates to remind you of the options and formatting for the different types of objects you might want to document using YARD.

First, add pry-rails to your Gemfile:
https://github.com/rweng/pry-rails

gem 'pry-rails', group: :development

Then you'll want to rebuild your Docker container to install the gems

	require "async"

	CONCURRENCY = 1000
	ITERATIONS = 100

	def work
	Async do \|task\|
	CONCURRENCY.times do
	task.async do
	sleep 1

	batches = Queue.new
	Order.select(:id).find_in_batches do \|batch\|
	batches << batch.map(&:id)
	end
	cpu_available.times do
	Thread.new do
	while(ids = batches.pop)
	pid = Process.fork do
	Sunspot.index! Order.includes(:product).find(ids)
	end

	class ParseEntries
	def process(message)
	entry = JSON.parse(message.value)
	[entry]
	end
	end

	class CombineEntries
	def initialize
	@open_transactions = {}