Cloudera Engineering Blog · Hadoop Posts

"Hadoop: The Definitive Guide" is Now a 4th Edition

Apache Hadoop ecosystem, time to celebrate! The much-anticipated, significantly updated 4th edition of Tom White’s classic O’Reilly Media book, Hadoop: The Definitive Guide, is now available.

The Hadoop ecosystem has changed a lot since the 3rd edition. How are those changes reflected in the new edition?

Converting Apache Avro Data to Parquet Format in Apache Hadoop

Thanks to Big Data Solutions Architect Matthieu Lieber for allowing us to republish the post below.

A customer of mine wants to take advantage of both worlds: work with his existing Apache Avro data, with all of the advantages that it confers, but take advantage of the predicate push-down features that Parquet provides. How to reconcile the two?

Understanding HDFS Recovery Processes (Part 2)

Having a good grasp of HDFS recovery processes is important when running or moving toward production-ready Apache Hadoop. In the conclusion to this two-part post, pipeline recovery is explained.

An important design requirement of HDFS is to ensure continuous and correct operations that support production deployments. For that reason, it’s important for operators to understand how HDFS recovery processes work. In Part 1 of this post, we looked at lease recovery and block recovery. Now, in Part 2, we explore pipeline recovery.

Understanding HDFS Recovery Processes (Part 1)

Having a good grasp of HDFS recovery processes is important when running or moving toward production-ready Apache Hadoop.

An important design requirement of HDFS is to ensure continuous and correct operations to support production deployments. One particularly complex area is ensuring correctness of writes to HDFS in the presence of network and node failures, where the lease recovery, block recovery, and pipeline recovery processes come into play. Understanding when and why these recovery processes are called, along with what they do, can help users as well as developers understand the machinations of their HDFS cluster.

Couchdoop: Couchbase Meets Apache Hadoop

Thanks to Călin-Andrei Burloiu, Big Data Engineer at antivirus company Avira, and Radu Pastia, Senior Software Developer in the Big Data Team at Orange, for the guest post below about the Couchdoop connector for bringing Couchbase data into Hadoop.

Couchdoop is a Couchbase connector for Apache Hadoop, developed by Avira on CDH, that allows for easy, parallel data transfer between Couchbase and Hadoop storage engines. It includes a command-line tool, for simple tasks and prototyping, as well as a MapReduce library, for those who want to use Couchdoop directly in MapReduce jobs. Couchdoop works natively with CDH 5.x.
Couchdoop can help you:

This Month in the Ecosystem (January 2015)

Welcome to our 16th edition of “This Month in the Ecosystem,” a digest of highlights from January 2015 (never intended to be comprehensive; for that, see the excellent Hadoop Weekly). 

You may have noticed that this report went on hiatus for December 2014 due to a lack of critical news mass (plus, we realize that most of you are out of the loop until mid-January). It’s back with a vengeance, though:

Tutorials at Strata + Hadoop World San Jose: Architecture, Hadoop Ops, Interactive SQL-on-Hadoop

Strata + Hadoop World San Jose 2015 (Feb. 17-20) is a focal point for learning about production-izing Hadoop.

Strata + Hadoop World sessions have always been indispensable for learning about Hadoop internals, use cases, and admin best practices. When deep learning is needed, however—and deep dives are a necessity if you’re running Hadoop in production, or aspire to—tutorials are your ticket.

How-to: Deploy Apache Hadoop Clusters Like a Boss

Learn how to set up a Hadoop cluster in a way that maximizes successful production-ization of Hadoop and minimizes ongoing, long-term adjustments.

Previously, we published some recommendations on selecting new hardware for Apache Hadoop deployments. That post covered some important ideas regarding cluster planning and deployment such as workload profiling and general recommendations for CPU, disk, and memory allocations. In this post, we’ll provide some best practices and guidelines for the next part of the implementation process: configuring the machines once they arrive. Between the two posts, you’ll have a great head start toward production-izing Hadoop.

New Advanced Analytics and Data Wrangling Tutorials on Cloudera Live

A new Spark tutorial and Trifacta deployment option make Cloudera Live even more useful for getting started with Apache Hadoop.

When it comes to learning Hadoop and CDH (Cloudera’s open source platform including Hadoop), there is no better place to start than Cloudera Live (  With a quick, one-button deployment option, Cloudera Live launches a four-node Cloudera cluster that you can learn and experiment in free for two-weeks. To help plan and extend the capabilities of your cluster, we also offer various partner deployments. Building on the addition of interactive tutorials and Tableau and Zoomdata integration, we have added a new tutorial on Apache Spark and a new Trifacta partner deployment.

New in CDH 5.3: Transparent Encryption in HDFS

Support for transparent, end-to-end encryption in HDFS is now available and production-ready (and shipping inside CDH 5.3 and later). Here’s how it works.

Apache Hadoop 2.6 adds support for transparent encryption to HDFS. Once configured, data read from and written to specified HDFS directories will be transparently encrypted and decrypted, without requiring any changes to user application code. This encryption is also end-to-end, meaning that data can only be encrypted and decrypted by the client. HDFS itself never handles unencrypted data or data encryption keys. All these characteristics improve security, and HDFS encryption can be an important part of an organization-wide data protection story.

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