stevesun21

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

Create a EC2 instance using Ubuntu 14.04.
In Secure Group Inbound Rules, add a SSH Rule(TCP, Port 22, 0.0.0.0/0) and a Custom TCP Rule(TCP, Port 1723, 0.0.0.0/0).
Optional: Associate a Elastic IP with the instance.
SSH into the instance.
sudo apt-get install pptpd.
sudo vim /etc/pptpd.conf. Uncomment localip 192.168.0.1 and remoteip 192.168.0.234-238,192.168.0.245.
sudo vim /etc/ppp/pptpd-options. Uncomment ms-dns and ms-wins. Change the IP to Google's DNS like this:

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

This is a simple way to backup your MySQL tables to Amazon S3 for a nightly backup - this is all to be done on your server :-)

Sister Document - Restore MySQL from Amazon S3 - read that next

this is for Centos 5.6, see http://s3tools.org/repositories for other systems like ubuntu etc

	import com.datastax.driver.core.*;

	import java.util.ArrayList;
	import java.util.Iterator;
	import java.util.List;

	/**
	* This is a helper class for implementing a pagination function based on Cassandra Java Driver (http://datastax.github.io/java-driver/)
	*
	* The solution of skipping rows is that use page state rather than iterator rows one by one.

	//
	// LoggingPrint.swift
	//

	import Foundation

	/**
	Prints the filename, function name, line number and textual representation of `object` and a newline character into
	the standard output if the build setting for "Active Complilation Conditions" (SWIFT_ACTIVE_COMPILATION_CONDITIONS) defines `DEBUG`.

	#!/bin/bash -ex
	# Wrapper for 'docker save' fixing,
	# https://github.com/dotcloud/docker/issues/3877
	# In addition: this script will always save exactly one image (possibly
	# multiple tags).

	IMAGE=$1
	TARGET=$2
	NAME=`echo $IMAGE \| awk -F':' '{print $1}'`
	ID=`docker inspect $IMAGE \| python -c "import sys,json; print json.load(sys.stdin)[0]['id']"`

	FROM ubuntu
	MAINTAINER "Bobby Wilson"
	RUN apt-get update
	RUN apt-get install curl -y
	RUN cd /usr/local; curl -O http://nodejs.org/dist/v0.10.16/node-v0.10.16-linux-x64.tar.gz
	RUN cd /usr/local; tar xzf node-v0.10.16-linux-x64.tar.gz
	ENV PATH /usr/local/bin:/usr/sbin:/bin:/usr/local/node-v0.10.16-linux-x64/bin
	ADD . /app
	EXPOSE 8000:8000
	ENV PORT 8000

	import java.lang.reflect.Type;

	import android.util.Base64;

	import com.google.gson.Gson;
	import com.google.gson.GsonBuilder;
	import com.google.gson.JsonDeserializationContext;
	import com.google.gson.JsonDeserializer;
	import com.google.gson.JsonElement;
	import com.google.gson.JsonParseException;

	public class NumberWordingTranslator {

	private final static String[] hundredWords={
	"Zero", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine",
	"Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen",
	"Twenty", null, null, null, null, null, null, null, null, null,
	"Thirty", null, null, null, null, null, null, null, null, null,
	"Forty", null, null, null, null, null, null, null, null, null,
	"Fifty", null, null, null, null, null, null, null, null, null,
	"Sixty", null, null, null, null, null, null, null, null, null,