Oshan Wisumperuma oshanz

Contract Killer

The popular open-source contract for web professionals by Stuff & Nonsense

Originally published: 23rd December 2008
Revised date: March 15th 2016
Original post

http://robots.thoughtbot.com/post/47202759358/using-gdb-to-inspect-a-running-ruby-process

That’s not a great thing to have to say, is it? However, I bet you’ve said it before and may not have immediately know why.

With liberal use of puts and maybe pry, you can figure out what a problem might be next time you run it, but sometimes you need to figure out what that problem is right now.

As it turns out, and I know this is a shocker, Ruby processes are just regular processes. They can be debugged with gdb.

Having recently had the need to find out why a job of mine was running particularly slowly, I found out about this lovely tool the hard way: frantic googling. I found some very useful functions for gdb in a blog post by Rasmus on Ruby callstacks.

	<%
	DEFAULT_DB = 'myapp_development'
	DB_BRANCHES = %w[ t79 ]
	branch = `git symbolic-ref HEAD 2> /dev/null`.chomp.split('/').last
	dev_db = DB_BRANCHES.include?(branch) ? branch.gsub(/[^a-zA-Z0-9_]/, '') : DEFAULT_DB
	puts "Using dev database: #{dev_db.inspect}"
	%>
	development:
	database: <%= dev_db %>

	## From a post on the ML, apropos this:
	## http://lowlatencyweb.wordpress.com/2012/03/20/500000-requestssec-modern-http-servers-are-fast.
	## For sysctl.conf

	net.ipv4.tcp_slow_start_after_idle = 0


	echo "2048 64512" > /proc/sys/net/ipv4/ip_local_port_range
	echo "1" > /proc/sys/net/ipv4/tcp_tw_recycle
	echo "1" > /proc/sys/net/ipv4/tcp_tw_reuse

	# Keep delayed job workers running using systemd on ubuntu
	# Usage
	# Start "sudo systemctl start delayed_job@{0..3}" to start 4 worker instances
	# Enable "sudo systemctl enable delayed_job@{0..3}" to enable 4 worker instances
	# Restart "sudo systemctl restart delayed_job@{0..3}" to restart 4 worker instances
	# Disable "sudo systemctl disable delayed_job@{0..3}" to disable 4 worker instances
	# Stop "sudo systemctl stop delayed_job@{0..3}" to stop 4 worker instances

	[Unit]
	Description=Delayed Job Worker %i

	<?php

	namespace H57\Util;

	class Serializor {

	/**
	* Converts the Doctrine Entity into a JSON Representation
	*
	* @param object $object The Object (Typically a Doctrine Entity) to convert to an array

	/* Adapted from Tom Cunningham's 'Data Warehousing with MySql' (www.meansandends.com/mysql-data-warehouse) */

	###### small-numbers table
	DROP TABLE IF EXISTS numbers_small;
	CREATE TABLE numbers_small (number INT);
	INSERT INTO numbers_small VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);

	###### main numbers table
	DROP TABLE IF EXISTS numbers;
	CREATE TABLE numbers (number BIGINT);

	alert(([][[]]+[])[!+[]+!![]+!![]+!![]]+([]
	[[]]+[])[+[]]+(!![]+[])[+[]]+([][[]]+[])
	[+[]]+([]+{})[!+[]+!![]]+([][[]]+[])[!
	+[]+!![]+!![]+!![]+!![]]+(![]+[])[!+[]+!!
	[]]+([][[]]+[])[!+[]+!![]+!![]]+([][[]]+[])
	[!+[]+!![]+!![]]+(!![]+[])[+[]])