Tushar Sharma tusharf5

Change SSH Port on Amazon EC2 Instance

1. Launch and connect to EC2 instance running Amazon Linux 2.
2. Promote to root and edit /etc/ssh/sshd_config 
## sudo vi /etc/ssh/sshd_config
3. Edit line 17 (usually 17) #PORT 22. You'll need to un-comment the line and change the port to whatever you like. 
## PORT 9222
4. Save changes and exit
## :wq

Starter Script or User Data (NGINX as Reverse Proxy for Node.js with PM2) [Amazon Linux 2]

Install Git
Install Nginx
Setup Nginx as a Reverse Proxy for your Node.js Application
Install Node using NVM
Install PM2
Run a Dummy API Server Using express
Start the Server using PM2
Auto Start PM2 after a server reboot.

Reading Big Files in Node.js is a little tricky. Node.js is meant to deal with I/O tasks efficiently and not CPU intensive computations. It is still doable though but I'd prefer doing such tasks in languages like python, R etc. Reading, Parsing, Transforming and then Saving large data sets (I'm talking millions of records here) can be done in a lot of ways but only a few of those are efficient. Following snippet is able to parse millions of records without wasting a lot of CPU (15% - 30% max) and (40 MB - 60 MB max) memory. It is based on Streams.

The following program expects the input to be a csv file source eg. big-data.unpr.csv It saves the result as ndjson and not json as working with huge datasets is easier when done using ndjson format.

	#listener {
	width: 45px;
	height: 45px;
	border: 1px solid black;
	}

	function splitPath(path) {
	const paths = [];

	for (let i = 0; i < path.length; i++) {
	const c = path[i];

	if (c === ']') {
	continue;
	}


	.file-node-content {
	padding: 9px 4px;
	margin: 0;
	display: flex;
	align-items: center;
	}

	.file-tree-node > .file-node-children {
	padding-left: 12px;

	export HOME="/Users/<USERNAME>"
	export PATH=$HOME/bin:/usr/local/bin:$PATH
	export PATH="/opt/local/bin:/opt/local/sbin:$PATH"
	export PATH="$HOME/.yarn/bin:$HOME/.config/yarn/global/node_modules/.bin:$PATH"
	# Path to your oh-my-zsh installation.
	export ZSH="$HOME/.oh-my-zsh"

	export LANG=en_US.UTF-8
	export LC_ALL=en_US.UTF-8

	{
	"Use Non-ASCII Font" : true,
	"Tags" : [

	],
	"Ansi 12 Color" : {
	"Green Component" : 0.57647058823529407,
	"Red Component" : 0.74117647058823533,
	"Blue Component" : 0.97647058823529409
	},

	Parameters:
	EnvironmentName:
	Description: An environment name that will be prefixed to resource names
	Type: String

	VpcCIDR:
	Description: Please enter the IP range (CIDR notation) for this VPC
	Type: String
	Default: 10.0.0.0/16

	user nginx;
	worker_processes auto;
	include /usr/share/nginx/modules/*.conf;
	events {
	worker_connections 1024;
	}
	http {
	sendfile on;
	tcp_nopush on;
	tcp_nodelay on;