Cheng-Hsiu (Jash) Lee s905060

ANNOUNCEMENT

I have moved this over to the Tech Interview Cheat Sheet Repo and has been expanded and even has code challenges you can run and practice against!

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Adding 2 nodes to an existing 3-node ZooKeeper ensemble without losing the Quorum

Since many deployments may start out with 3 nodes and so little is known about how to grow a cluster from 3 memebrs to 5 members without losing the existing Quorum, here is an example of how this might be achieved.

In this example, all 5 nodes will be running on the same Vagrant host for the purpose of illustration, running on distinct configurations (ports and data directories) without the actual load of clients.

YMMV. Caveat usufructuarius.

Step 1: Have a healthy 3-node ensemble

#Linux - Running a Node Service (PM2) PM2 is a replacement for Forever which is used to run Node services (see http://devo.ps/blog/2013/06/26/goodbye-node-forever-hello-pm2.html). It has a number of advantages over forever:

Log aggregation
API
Terminal monitoring
Clustering
JSON configuration

	======
	Videos
	======

	DevOps

	What is DevOps? by Rackspace - Really great introduction to DevOps
	https://www.youtube.com/watch?v=_I94-tJlovg

	Sanjeev Sharma series on DevOps (great repetition to really get the DevOps concept)

	-- login to vsql
	vsql -Ulogin -wpassword

	-- number of running processes
	ps -ef \| grep -i vertica-udx-R \| wc -l

	-- list all nodes thet are UP
	admintools -t list_allnodes \| grep UP

	-- restart a node

	http://answers.oreilly.com/topic/460-how-to-benchmark-a-hadoop-cluster/
	http://www.michael-noll.com/blog/2011/04/09/benchmarking-and-stress-testing-an-hadoop-cluster-with-terasort-testdfsio-nnbench-mrbench/

	## MR pi
	https://gist.github.com/jeongho/371aaed47ab462d79851

	## Terasort
	https://gist.github.com/jeongho/3b8c028f5e8409c3a10a

	## TestDFSIO

	import signal
	import sys

	def signal_term_handler(signal, frame):
	print 'got SIGTERM'
	sys.exit(0)

	signal.signal(signal.SIGTERM, signal_term_handler)

	Byobu Commands
	==============

	byobu Screen manager


	Level 0 Commands (Quick Start)
	------------------------------

	<F2> Create a new window

	# I needed to print out ascii tables from data in the form:
	# [ ('column 0 title', 'column 1 title' ..),
	# ('row 0, column 0 data', 'row 0, column 1 data' ...) ...]
	#
	# and surprisingly it got complicated because of variable lengths of the data.
	# I googled for 'standard' ways of doing this and I found suggestions like:
	# http://stackoverflow.com/questions/5909873/python-pretty-printing-ascii-tables
	# ...which were a bit dated and hard to read or full scale modules like:
	#
	# http://pypi.python.org/pypi/texttable/

Cheng-Hsiu (Jash) Lee s905060

ANNOUNCEMENT

Adding 2 nodes to an existing 3-node ZooKeeper ensemble without losing the Quorum

Step 1: Have a healthy 3-node ensemble

Installation