LXHING999

System Design Cheatsheet

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

Basic Steps

Clarify and agree on the scope of the system

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?

layout

title

description

Purpose

A curated list of AWS resources to prepare for the AWS Certifications

A curated list of awesome AWS resources you need to prepare for the all 5 AWS Certifications. This gist will include: open source repos, blogs & blogposts, ebooks, PDF, whitepapers, video courses, free lecture, slides, sample test and many other resources.

For more about AWS and AWS Certifications and updates to this Gist you should follow me @leonardofed

docker用来隔离应用还是很方便的，一来本身的操作较为简单，二来资源占用也比虚拟机要小得多，三来也较为安全，因为像数据库这样的应用不会再全局暴露端口，同时应用间的通信通过加密和端口转发，更加安全。

Gitlab是目前比较流行的开源类Github代码管理平台。Gitlab使用Rails开发，使用PostgreSQL或MySQL数据库，Redis做缓存。一般自己搭建私有代码仓库，Gitlab通常是首选。这里简单介绍一下dockerized Gitlab。

Gitlab的docker镜像早已有人做好了，并且维护相当不错。大家可以前往其GitHub仓库了解该镜像的情况。官方repo的readme中已经有详细的安装配置方案，这里我简单的梳理一下部署流程。

安装Docker

这里以Ubuntu 14.04发行版为例，在bash中输入一下命令安装最新的docker：

	##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### #####

	### Shell script to download Oracle JDK / JRE / Java binaries from Oracle website using terminal / command / shell prompt using wget.
	### You can download all the binaries one-shot by just giving the BASE_URL.
	### Script might be useful if you need Oracle JDK on Amazon EC2 env.
	### Script is updated for every JDK release.

	### Features:-
	# 1. Resumes a broken / interrupted [previous] download, if any.
	# 2. Renames the file to a proper name with including platform info.

	import javax.net.ssl.SSLSocket;
	import javax.net.ssl.SSLSocketFactory;
	import java.io.*;

	/** Establish a SSL connection to a host and port, writes a byte and
	* prints the response. See
	* http://confluence.atlassian.com/display/JIRA/Connecting+to+SSL+services
	*/
	public class SSLPoke {
	public static void main(String[] args) {

	import java.io.IOException;
	import java.net.URLClassLoader;
	import java.nio.file.Files;
	import java.nio.file.Paths;
	import java.nio.file.Path;

	/**
	* Example demonstrating a ClassLoader leak.
	*
	* <p>To see it in action, copy this file to a temp directory somewhere,

	# Compiled source #
	###################
	*.com
	*.class
	*.dll
	*.exe
	*.o
	*.so

	# Packages #

	WITH table_scans as (
	SELECT relid,
	tables.idx_scan + tables.seq_scan as all_scans,
	( tables.n_tup_ins + tables.n_tup_upd + tables.n_tup_del ) as writes,
	pg_relation_size(relid) as table_size
	FROM pg_stat_user_tables as tables
	),
	all_writes as (
	SELECT sum(writes) as total_writes
	FROM table_scans

	CREATE TABLE IF NOT EXISTS `country` (
	`id` int(11) NOT NULL AUTO_INCREMENT,
	`iso` char(2) NOT NULL,
	`name` varchar(80) NOT NULL,
	`nicename` varchar(80) NOT NULL,
	`iso3` char(3) DEFAULT NULL,
	`numcode` smallint(6) DEFAULT NULL,
	`phonecode` int(5) NOT NULL,
	PRIMARY KEY (`id`)
	) ENGINE=MyISAM DEFAULT CHARSET=latin1;