Patrick Cieplak cieplak

Virtual Hosts on nginx (CSC309)

When hosting our web applications, we often have one public IP address (i.e., an IP address visible to the outside world) using which we want to host multiple web apps. For example, one may wants to host three different web apps respectively for example1.com, example2.com, and example1.com/images on the same machine using a single IP address.

How can we do that? Well, the good news is Internet browsers

Perl Encryption Primer

by Timm Murray

This is a compilation of the "Perl Encryption Primer" series of articles by Timm Murray, as published on http://www.wumpus-cave.net/category/encryption/. I have taken the liberty of moving the content here (as is), formatting it as Markdown and ordering them chronologically from top to bottom to easen the reading experience. Enjoy!

Timm also made a one-hour video of the presentation he gave at MadMongers, which summarizes the content below.

	#!/usr/bin/env bash
	#
	# File: kafka-move-leadership.sh
	#
	# Description
	# ===========
	#
	# Generates a Kafka partition reassignment JSON snippet to STDOUT to move the leadership
	# of any replicas away from the provided "source" broker to different, randomly selected
	# "target" brokers. Run this script with `-h` to show detailed usage instructions.

	import Control.Concurrent.MVar

	type Channel a = (ReadPort a, WritePort a)
	type ReadPort a = MVar (Stream a)
	type WritePort a = MVar (Stream a)
	type Stream a = MVar (Item a)
	data Item a = MkItem a (Stream a)

	newChan :: IO (Channel a)
	newChan = do

	{-# LANGUAGE OverloadedStrings #-}

	module SimpleThings where

	import Control.Applicative ((<$>), (<*>))
	import Control.Monad (mzero)
	import Data.Aeson
	import qualified Data.Aeson as A

	-- \| sum type containing all possible payloads

	import static java.lang.System.*;

	import java.util.function.BiFunction;
	import java.util.function.Function;

	// Implementation of a pseudo-GADT in Java, translating the examples from
	// http://www.cs.ox.ac.uk/ralf.hinze/publications/With.pdf
	// The technique presented below is, in fact, just an encoding of a normal Algebraic Data Type
	// using a variation of the visitor pattern + the application of the Yoneda lemma to make it
	// isomorphic to the targeted 'GADT'.

	import Control.Monad

	-------------------------------------------------------------------------------
	-- State Monad Implementation
	-------------------------------------------------------------------------------

	newtype State s a = State { runState :: s -> (a,s) }

	instance Monad (State s) where
	return a = State $ \s -> (a, s)

	# ----------------------
	# Status Bar
	# -----------------------
	set-option -g status on # turn the status bar on
	set -g status-utf8 on # set utf-8 for the status bar
	set -g status-interval 5 # set update frequencey (default 15 seconds)
	set -g status-justify centre # center window list for clarity
	# set-option -g status-position top # position the status bar at top of screen

	# visual notification of activity in other windows

	Producer

	Setup
	bin/kafka-topics.sh --zookeeper esv4-hcl197.grid.linkedin.com:2181 --create --topic test-rep-one --partitions 6 --replication-factor 1
	bin/kafka-topics.sh --zookeeper esv4-hcl197.grid.linkedin.com:2181 --create --topic test --partitions 6 --replication-factor 3

	Single thread, no replication

	bin/kafka-run-class.sh org.apache.kafka.clients.tools.ProducerPerformance test7 50000000 100 -1 acks=1 bootstrap.servers=esv4-hcl198.grid.linkedin.com:9092 buffer.memory=67108864 batch.size=8196