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Introduction to Kafka

Kafka acts as a kind of write-ahead log (WAL) that records messages to a persistent store (disk) and allows subscribers to read and apply these changes to their own stores in a system appropriate time-frame.

Terminology:

Producers send messages to brokers
Consumers read messages from brokers
Messages are sent to a topic

Installing SSHPASS

SSHPass is a tiny utility, which allows you to provide the ssh password without using the prompt. This will very helpful for scripting. SSHPass is not good to use in multi-user environment. If you use SSHPass on your development machine, it don't do anything evil.

Installing on Ubuntu

apt-get install sshpass

Installing on OS X

CSS Layout Debugger

A tweet-sized debugger for visualizing your CSS layouts. Outlines every DOM element on your page a random (valid) CSS hex color.

One-line version to paste in your DevTools

Use $$ if your browser aliases it:

~ 108 byte version

There are certain files created by particular editors, IDEs, operating systems, etc., that do not belong in a repository. But adding system-specific files to the repo's .gitignore is considered a poor practice. This file should only exclude files and directories that are a part of the package that should not be versioned (such as the node_modules directory) as well as files that are generated (and regenerated) as artifacts of a build process.

All other files should be in your own global gitignore file:

Create a file called .gitignore in your home directory and add any filepath patterns you want to ignore.
Tell git where your global gitignore file is.

Note: The specific name and path you choose aren't important as long as you configure git to find it, as shown below. You could substitute .config/git/ignore for .gitignore in your home directory, if you prefer.

	import org.junit.Test;
	import java.util.Date;
	import static org.junit.Assert.assertEquals;

	public class StringFormatTest {

	@Test public void basicInteger() {
	assertEquals("123456", String.format("%d", 123456));
	}

	# based on http://uberblo.gs/2011/06/high-performance-url-shortening-with-redis-backed-nginx
	# using code from http://stackoverflow.com/questions/3554315/lua-base-converter

	# "database scheme"
	# database 0: id ~> url
	# database 1: id ~> hits
	# database 2: id ~> [{referer\|user_agent}]
	# database 3: id ~> hits (when id is not found)
	# database 4: id ~> [{referer\|user_agent}] (when id is not found)
	# database 5: key "count" storing the number of shortened urls; the id is generated by (this number + 1) converted to base 62

	-- Two dashes start a one-line comment.

	--[[
	Adding two ['s and ]'s makes it a
	multi-line comment.
	--]]

	----------------------------------------------------
	-- 1. Variables and flow control.
	----------------------------------------------------

	// Traverses an arbitrary struct and translates all stings it encounters
	//
	// I haven't seen an example for reflection traversing an arbitrary struct, so
	// I want to share this with you. If you encounter any bugs or want to see
	// another example please comment.
	//
	// The MIT License (MIT)
	//
	// Copyright (c) 2014 Heye Vöcking
	//

	package main

	import (
	"fmt"
	"reflect"
	)

	func Decorate(impl interface{}) interface{} {
	fn := reflect.ValueOf(impl)

	package main

	import (
	"database/sql"
	"database/sql/driver"
	"errors"
	"fmt"
	_ "github.com/mattn/go-sqlite3"
	)