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  • Book Overview & Buying Hadoop MapReduce v2 Cookbook - Second Edition: RAW
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Hadoop MapReduce v2 Cookbook - Second Edition: RAW

Hadoop MapReduce v2 Cookbook - Second Edition: RAW - Second Edition

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Hadoop MapReduce v2 Cookbook - Second Edition: RAW

Hadoop MapReduce v2 Cookbook - Second Edition: RAW

4.4 (7)
Buy this Book

Overview of this book

If you are a Big Data enthusiast and wish to use Hadoop v2 to solve your problems, then this book is for you. This book is for Java programmers with little to moderate knowledge of Hadoop MapReduce. This is also a one-stop reference for developers and system admins who want to quickly get up to speed with using Hadoop v2. It would be helpful to have a basic knowledge of software development using Java and a basic working knowledge of Linux.
Table of Contents (12 chapters)
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Preface
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Preface
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What this book covers
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What you need for this book
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Who this book is for
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Conventions
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Reader feedback
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Customer support
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1
1. Getting Started with Hadoop v2
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1. Getting Started with Hadoop v2
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Introduction
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Setting up Hadoop v2 on your local machine
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Writing a WordCount MapReduce application, bundling it, and running it using the Hadoop local mode
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Adding a combiner step to the WordCount MapReduce program
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Setting up HDFS
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Setting up Hadoop YARN in a distributed cluster environment using Hadoop v2
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Setting up Hadoop ecosystem in a distributed cluster environment using a Hadoop distribution
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HDFS command-line file operations
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Running the WordCount program in a distributed cluster environment
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Benchmarking HDFS using DFSIO
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Benchmarking Hadoop MapReduce using TeraSort
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2. Cloud Deployments – Using Hadoop YARN on Cloud Environments
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2. Cloud Deployments – Using Hadoop YARN on Cloud Environments
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Introduction
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Running Hadoop MapReduce v2 computations using Amazon Elastic MapReduce
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Saving money using Amazon EC2 Spot Instances to execute EMR job flows
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Executing a Pig script using EMR
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Executing a Hive script using EMR
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Creating an Amazon EMR job flow using the AWS Command Line Interface
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Deploying an Apache HBase cluster on Amazon EC2 using EMR
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Using EMR bootstrap actions to configure VMs for the Amazon EMR jobs
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Using Apache Whirr to deploy an Apache Hadoop cluster in a cloud environment
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3. Hadoop Essentials – Configurations, Unit Tests, and Other APIs
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3. Hadoop Essentials – Configurations, Unit Tests, and Other APIs
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Introduction
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Optimizing Hadoop YARN and MapReduce configurations for cluster deployments
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Shared user Hadoop clusters – using Fair and Capacity schedulers
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Setting classpath precedence to user-provided JARs
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Speculative execution of straggling tasks
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Unit testing Hadoop MapReduce applications using MRUnit
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Integration testing Hadoop MapReduce applications using MiniYarnCluster
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Adding a new DataNode
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Decommissioning DataNodes
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Using multiple disks/volumes and limiting HDFS disk usage
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Setting the HDFS block size
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Setting the file replication factor
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Using the HDFS Java API
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4. Developing Complex Hadoop MapReduce Applications
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4. Developing Complex Hadoop MapReduce Applications
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Introduction
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Choosing appropriate Hadoop data types
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Implementing a custom Hadoop Writable data type
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Implementing a custom Hadoop key type
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Emitting data of different value types from a Mapper
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Choosing a suitable Hadoop InputFormat for your input data format
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Adding support for new input data formats – implementing a custom InputFormat
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Formatting the results of MapReduce computations – using Hadoop OutputFormats
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Writing multiple outputs from a MapReduce computation
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Hadoop intermediate data partitioning
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Secondary sorting – sorting Reduce input values
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Broadcasting and distributing shared resources to tasks in a MapReduce job – Hadoop DistributedCache
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Using Hadoop with legacy applications – Hadoop streaming
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Adding dependencies between MapReduce jobs
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Hadoop counters to report custom metrics
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5. Analytics
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5. Analytics
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Introduction
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Simple analytics using MapReduce
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Performing GROUP BY using MapReduce
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Calculating frequency distributions and sorting using MapReduce
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Plotting the Hadoop MapReduce results using gnuplot
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Calculating histograms using MapReduce
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Calculating Scatter plots using MapReduce
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Parsing a complex dataset with Hadoop
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Joining two datasets using MapReduce
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6. Hadoop Ecosystem – Apache Hive
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6. Hadoop Ecosystem – Apache Hive
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Introduction
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Getting started with Apache Hive
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Creating databases and tables using Hive CLI
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Simple SQL-style data querying using Apache Hive
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Creating and populating Hive tables and views using Hive query results
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Utilizing different storage formats in Hive - storing table data using ORC files
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Using Hive built-in functions
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Hive batch mode - using a query file
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Performing a join with Hive
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Creating partitioned Hive tables
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Writing Hive User-defined Functions (UDF)
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HCatalog – performing Java MapReduce computations on data mapped to Hive tables
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HCatalog – writing data to Hive tables from Java MapReduce computations
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7. Hadoop Ecosystem II – Pig, HBase, Mahout, and Sqoop
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7. Hadoop Ecosystem II – Pig, HBase, Mahout, and Sqoop
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Introduction
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Getting started with Apache Pig
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Joining two datasets using Pig
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Accessing a Hive table data in Pig using HCatalog
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Getting started with Apache HBase
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Data random access using Java client APIs
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Running MapReduce jobs on HBase
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Using Hive to insert data into HBase tables
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Getting started with Apache Mahout
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Running K-means with Mahout
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Importing data to HDFS from a relational database using Apache Sqoop
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Exporting data from HDFS to a relational database using Apache Sqoop
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8. Searching and Indexing
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8. Searching and Indexing
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Introduction
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Generating an inverted index using Hadoop MapReduce
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Intradomain web crawling using Apache Nutch
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Indexing and searching web documents using Apache Solr
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Configuring Apache HBase as the backend data store for Apache Nutch
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Whole web crawling with Apache Nutch using a Hadoop/HBase cluster
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Elasticsearch for indexing and searching
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Generating the in-links graph for crawled web pages
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9. Classifications, Recommendations, and Finding Relationships
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9. Classifications, Recommendations, and Finding Relationships
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Introduction
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Performing content-based recommendations
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Classification using the naïve Bayes classifier
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Assigning advertisements to keywords using the Adwords balance algorithm
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10. Mass Text Data Processing
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10. Mass Text Data Processing
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Introduction
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Data preprocessing using Hadoop streaming and Python
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De-duplicating data using Hadoop streaming
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Loading large datasets to an Apache HBase data store – importtsv and bulkload
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Creating TF and TF-IDF vectors for the text data
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Clustering text data using Apache Mahout
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Topic discovery using Latent Dirichlet Allocation (LDA)
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Document classification using Mahout Naive Bayes Classifier
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Index
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Index

Calculating histograms using MapReduce

Another interesting view of a dataset is a histogram. A histogram makes sense only under a continuous dimension (for example, accessed time and file size). It groups the number of occurrences of an event into several groups in the dimension. For example, in this recipe, if we take the accessed time as the dimension, then we will group the accessed time by the hour.

The following figure shows the execution summary of this computation. The Mapper emits the hour of the access as the key and 1 as the value. Then, each reduce function invocation receives all the occurrences of a certain hour of the day, and it calculates the total number of occurrences for that hour of the day.

Getting ready

This recipe assumes that you have a working Hadoop installation. Install gnuplot.

How to do it...

The following steps show how to calculate and plot a histogram:

  1. Download the weblog dataset from ftp://ita.ee.lbl.gov/traces/NASA_access_log_Jul95.gz and extract it.

  2. Upload the...

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