Installing Hadoop 2.x on MAC (Yosemite)

After breaking my head on several videos and blogs i finally got it right.
To install hadoop 2.x on mac i would recommend you have
a) Java Installed (If java is not installed install JAVA JDK)
b) Password-less ssh
(Check by typing down below)

ssh localhost

If password-less ssh is not enabled
Ensure Remote Login under System Preferences -> Sharing is checked to enable SSH.

ssh-keygen -t rsa -P ""

cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys

ssh localhost

(Make sure you are able to ssh password less and while generating keys make sure its blank)
(For this tutorial we will configure Hadoop in psedu0-distributed mode -- http://hadoop.apache.org/docs/r2.7.0/hadoop-project-dist/hadoop-common/SingleCluster.html#Pseudo-Distributed_Operation)

Download Hadoop
Extract Hadoop

tar -xvzf ~/Downloads/hadoop-2.7.0.tar.gz

And edit the following in the configuration files

And Voilà you have a petit Hadoop cluster for yourself.

Building Pig from Source

Installing Ambari from scratch using Vagrant. Step by Step

Being a developer it a pain to configure hadoop every time.
I wanted a process that is easily reproducible.
So at a high level steps involved are:

Make sure you have vagrant installed
Config : 3 node , 3.4GB, 1 core each
1 master, 2 slaves
Create a vagrant file (Make sure you have more than 10GB Ram)

after creating this file all you need to do is 'vagrant up'

Step 1: FDQN
http://en.wikipedia.org/wiki/Fully_qualified_domain_name
change vi /etc/hosts

prepend with following entries
10.10.0.53   hdp.hadoop1.com hadoop1
10.10.0.54   hdp.hadoop2.com hadoop2
10.10.0.55   hdp.hadoop3.com hadoop3

(In All three nodes)
you should be able to ssh using domain names + 'hostname -f' returns fdqn for that machine

Install NTP and NTPD in all nodes

Use the script below to prepare your cluster
./prepare-cluster.sh hosts.txt


And Vola . Just run the commands below.

PS : Make sure you had entries to the hosts in Windows. Remember to check if the hostname is pingable from windows.

ping hdp.hadoop1.com

URL : hdp.hadoop1.com:8080

MapR SingleNode in Ubuntu

Creating a single node instance of MapR in ubuntu.

Using Pig to Load and Store data from HBase

Lets first store data from HDFS to our HBase Table. For this we will be using

org.apache.pig.backend.hadoop.hbase
Class HBaseStorage

public HBaseStorage(String columnList) throws org.apache.commons.cli.ParseException,IOException)

Warning: Make sure that your PIG_CLASSPATH refers to all the library files in HBASE,HADOOP and ZOOKEEPER. Doing this will save you countless hours of debugging.

Lets Create a HBase table for the data given below named as testtable.

Make sure that your first column is the ROWKEY while doing an insert to HBase table.



Lets Create a Table for this data in HBase.

>> cd $HBASE_HOME\bin
>> ./hbase shell

This will take you to your HBase shell

>> create 'testtable','cf'
>> list 'testtable'
>> scan 'testtable'

Now lets fire up grunt shell

Type in the following commands in the grunt shell

and TaDa....

Pig Casting and Schema Management

Pig is quite flexible when schema need to be manipulated.

Consider this data set



Suppose we needed to define schema after some processing we could cast the columns with their data types



That all for today folks.

Cheers!

Sum in Pig

This is a simple PigScript i wrote to understand the concepts of pig.
Well here it goes

Today we will see how to do a simple sum operation in Pig.

Consider this as my input data
.

The first example - sum
The second example - group and sum

Installing R with RStudio in Ubuntu

Helllo people,

lets start the installation by opening your terminal first.

and type in the flowering commands.

sudo apt-get install r-base

sudo apt-get install gdebi-core

sudo apt-get install libapparmor1

wget http://download2.rstudio.org/rstudio-server-0.98.1085-amd64.deb

sudo gdebi rstudio-server-0.98.1085-amd64.deb

and here you go with a brand new R-Studio.

Apache Pig Day 1

Hello People,
I increasingly spending more time working on pig. (Thankgod).
This experience has been very valuable as it has increased my knowledge on data.
Pig is an open source project.
Language for developing pig scripts is called pig latin.
Its easier to write pig script than mapreduce code (Its saves the developers time)
Pig is a dataflow language that means it allows the users to describe data.
Pig Latin Scripts are describes a DAG. Directed Acyclic Graph
Developed by Yahoo!.
Aim to this language is to find a sweet spot between SQL and Shell Scripts.
To sum it up Pig is you to build data pipelines / run ETL workloads.
 

TO DO List

This order is of importance...
a) Data Structures and Algorithms
b) Machine Learning
c) Dev Ops (Linux)
d) Start a youtube channel
e) Spring Framework Learn

I guess this will take a life time to master.

Currently preparing for Hadoop Admin Certification.

Pig

I will posting series of posts on Pig.

I personally feel amazed at the simplicity and the power of this language.

Pig Cheat Sheet:

http://mortar-public-site-content.s3-website-us-east-1.amazonaws.com/Mortar-Pig-Cheat-Sheet.pdf

Cheers!

Krishna

Crawling - Scrapy

What is Scrapy?

Scrapy is a fast high-level screen scraping and web crawling framework, used to crawl websites and extract structured data from their pages. It can be used for a wide range of purposes, from data mining to monitoring and automated testing.

Installation

OS Ubuntu

Installing Dependencies 

sudo apt-get install build-essential libssl-dev libffi-dev python-dev

Install scrapy

sudo pip install Scrapy

The above scripts will install scrapy

Algorithms

I am taking algorithms course in coursera.

Python week 4

Week 4 of coursera.
Been busy with odd jobs just not able to finish the assignments and be done with it.
I hope to complete all video lectures and assignments today.

Julia Meetup

I had an amazing experience organizing the first Julia meetup in Inmobi with Abhijit and Kiran.
Gave my first formal open source talk and it felt great.
Link to my slides - http://www.slideshare.net/KrishnaKalyan3/julia-meetup-bangalore