Ran Aroussi ranaroussi

What

Roll your own iPython Notebook server with Amazon Web Services (EC2) using their Free Tier.

What are we using? What do you need?

An active AWS account. First time sign-ups are eligible for the free tier for a year
One Micro Tier EC2 Instance
With AWS we will use the stock Ubuntu Server AMI and customize it.
Anaconda for Python.
Coffee/Beer/Time

-- Firstly, remove PRIMARY KEY attribute of former PRIMARY KEY
ALTER TABLE <table_name> DROP CONSTRAINT <table_name>_pkey;

-- Then change column name of  your PRIMARY KEY and PRIMARY KEY candidates properly.
ALTER TABLE <table_name> RENAME COLUMN <primary_key_candidate> TO id;

Moved to git repository: https://github.com/denji/nginx-tuning

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

-E: will describe the underlaying queries of the \ commands (cool for learning!)
-l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

ZeroMQ vs Redis

This document is research for the selection of a communication platform for robot-net.

Goal

The purpose of this component is to enable rapid, reliable, and elegant communication between the various nodes of the network, including controllers, sensors, and actuators (robot drivers). It will act as the core of robot-net to create a standardized infrastructure for robot control.

Requirements:

	/*
	Polyfill for the Object.watch/Object.unwatch functions available in Mozilla browsers
	https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Object/watch

	you have a test here:
	http://www.telecable.es/personales/covam1/deployToNenyures/SourceCode/Object.watch.test.js

	and can read more here:
	http://deploytonenyures.blogspot.com.es/2013/02/objectwatch-polyfill.html
	*/

	import zmq

	def main():
	try:
	context = zmq.Context(1)

	frontend = context.socket(zmq.SUB)
	frontend.bind('tcp://*:5559')
	frontend.setsockopt(zmq.SUBSCRIBE, '')

	"""Hackish script to convert a notebook into

	Note that the content of markdown cells is not translated: it is assumed to
	hold asciidoc content instead (even if it does not render correctly in the
	browser editing the notebook file).

	This script could be improved to use pandoc to handle the conversion instead.

	Sample usage:

	{url:'stun:stun01.sipphone.com'},
	{url:'stun:stun.ekiga.net'},
	{url:'stun:stun.fwdnet.net'},
	{url:'stun:stun.ideasip.com'},
	{url:'stun:stun.iptel.org'},
	{url:'stun:stun.rixtelecom.se'},
	{url:'stun:stun.schlund.de'},
	{url:'stun:stun.l.google.com:19302'},
	{url:'stun:stun1.l.google.com:19302'},
	{url:'stun:stun2.l.google.com:19302'},

	tell application "QuickTime Player" to activate
	tell application "System Events"
	activate
	--set UI elements enabled to true
	tell process "QuickTime Player"
	click menu item "New Screen Recording" of menu "File" of menu bar 1
	end tell
	end tell

	tell application "QuickTime Player"