Cloudera Blog · CDH Posts
Introduction to Apache HBase Snapshots
The current (4.2) release of CDH — Cloudera’s 100% open-source distribution of Apache Hadoop and related projects (including Apache HBase) — introduced a new HBase feature, recently landed in trunk, that allows an admin to take a snapshot of a specified table.
Prior to CDH 4.2, the only way to back-up or clone a table was to use Copy/Export Table, or after disabling the table, copy all the hfiles in HDFS. Copy/Export Table is a set of tools that uses MapReduce to scan and copy the table but with a direct impact on Region Server performance. Disabling the table stops all reads and writes, which will almost always be unacceptable.
In contrast, HBase snapshots allow an admin to clone a table without data copies and with minimal impact on Region Servers. Exporting the snapshot to another cluster does not directly affect any of the Region Servers; export is just a distcp with an extra bit of logic.
How-to: Set Up a Hadoop Cluster with Network Encryption
- by Alejandro Abdelnur & Aaron T. Myers
- March 05, 2013
- no comments
Hadoop network encryption is a feature introduced in Apache Hadoop 2.0.2-alpha and in CDH4.1.
In this blog post, we’ll first cover Hadoop’s pre-existing security capabilities. Then, we’ll explain why network encryption may be required. We’ll also provide some details on how it has been implemented. At the end of this blog post, you’ll get step-by-step instructions to help you set up a Hadoop cluster with network encryption.
A Bit of History on Hadoop Security
Starting with Apache Hadoop 0.20.20x and available in Hadoop 1 and Hadoop 2 releases (as well as CDH3 and CDH4 releases), Hadoop supports Kerberos-based authentication. This is commonly referred to as Hadoop Security. When Hadoop Security is enabled it requires users to authenticate (using Kerberos) in order to read and write data in HDFS or to submit and manage MapReduce jobs. In addition, all Hadoop services authenticate with each other using Kerberos.
What’s New in Hue 2.2?
This post is about the new release of Hue, an open source web-based interface that makes Apache Hadoop easier to use, that’s included in CDH4.2.
Hue lets you interact with Hadoop services from within your browser without having to go to a command-line interface. It features a file browser for HDFS, an Apache Oozie Application for creating workflows of data processing jobs, a job designer/browser for MapReduce, Apache Hive and Cloudera Impala query editors, a Shell, and a collection of Hadoop APIs.
The goal of this release was to add a set of new features and improve the user experience. Read on for a list of the major changes (from 304 commits).
Oozie Application
New Products and Releases: Cloudera Navigator, Cloudera Enterprise BDR, and More
Today is an exciting day for Cloudera customers and users. With an update to our 100% open source platform and a number of new add-on products, every software component we ship is getting either a minor or major update. There’s a lot to cover and this blog post is only a summary. In the coming weeks we’ll do follow-on blog posts that go deeper into each of these releases.
New Products
We’re now supporting several hundred production Hadoop clusters. In doing so we’ve had to make a lot of advances in the functionality, reliability and manageability of the Hadoop platform. Even with these improvements, customers have been traditionally reluctant to run certain data and applications on the Apache Hadoop platform. The new products we are announcing today were designed to remove these obstacles to adoption.
How-To: Run a MapReduce Job in CDH4 using Advanced Features
In my previous post, you learned how to write a basic MapReduce job and run it on Apache Hadoop. In this post, we’ll delve deeper into MapReduce programming and cover some of the framework’s more advanced features. In particular, we’ll explore:
Ph.D. Interns at Cloudera: Bringing Big Data Back to School
The following is a series of stories from people who in the recent past worked as Engineering Interns at Cloudera. These experiences concretely illustrate how collaboration between commercial companies like Cloudera and academia, such as in the form of these internships, helps promote big data research at universities. (These experiences were previously published in the ACM student journal, XRDS.)
Yanpei Chen (Intern 2011)
I Interned with Cloudera during my last summer of grad school. My dissertation was on “Workload Driven Design and Evaluation of Large-Scale Data-Centric Systems”, and I already had collaborations with
Facebook and NetApp, two other big data companies. The goal of my work was to develop and demonstrate a set of empirical, workload-driven design and evaluation methods that complemented the traditional, subjective approach of designing by intuition and experience. It was very important that these methods generalized across many types of customer workloads. Hence, when Cloudera offered me an internship, I leapt at the unique opportunity to collect insights from customers in traditional industries who were still dealing with big data.
Webinar: Introduction to Hadoop Developer Training (Jan. 31)
Are you new to Apache Hadoop and need to start processing data fast and effectively? Have you been playing with CDH and are ready to move on to development supporting a technical or business use case? Are you prepared to unlock the full potential of all your data by building and deploying powerful Hadoop-based applications?
How-to: Deploy a CDH Cluster in Skytap Cloud
- by Matt Sousley
- January 23, 2013
- no comments
You may have seen the recent announcement from Skytap about the availability of pre-configured CDH4 templates in the Skytap Cloud public template library. So for anyone who wants to try out a Cloudera Hadoop cluster—from small to large—it can now be easily accomplished in Skytap Cloud. The how-to below from Skytap’s Matt Sousely explains how.
The goal of this how-to will be to spin up a 10-node Cloudera Hadoop cluster in Skytap Cloud. To begin, let’s talk about the two new Cloudera Hadoop cluster templates. The first is Cloudera CDH4 Hadoop cluster: a 2-node Hadoop cluster template. It includes 2 nodes and a management node/server. The second is the Cloudera CDH4 Hadoop host template. This second template is not intended to run by itself in a configuration—rather, it contains a host VM that is ready to become another Hadoop node in the Cloudera CDH4 Hadoop cluster template-based configuration.
To start, let’s spin up a Cloudera Hadoop cluster.
- Log in to Skytap Cloud
- Choose the Templates tab
- In the search box, type hadoop
- Select Cloudera CDH4 Hadoop cluster
- Click New Configuration
- Click Run

How-to: Do Apache Flume Performance Tuning (Part 1)
The post below was originally published via blogs.apache.org and is republished below for your reading pleasure.
This is Part 1 in a series of articles about tuning the performance of Apache Flume, a distributed, reliable, and available service for efficiently collecting, aggregating, and moving large amounts of event data.
To kick off this series, I’d like to start off discussing some important Flume concepts that come into play when tuning your Flume flows for maximum performance: the channel and the transaction batch size.
Setting Up a Data Flow
Apache Hadoop in 2013: The State of the Platform
For several good reasons, 2013 is a Happy New Year for Apache Hadoop enthusiasts.
In 2012, we saw continued progress on developing the next generation of the MapReduce processing framework (MRv2), work that will bear fruit this year. HDFS experienced major progress toward becoming a lights-out, fully enterprise-ready distributed filesystem with the addition of high availability features and increased performance. And a hint of the future of the Hadoop platform was provided with the Beta release of Cloudera Impala, a real-time query engine for analytics across HDFS and Apache HBase data.
Let’s look at the highlights of the 2012 developments around projects supported by Cloudera.