Cloudera Engineering Blog · Pig Posts

How-to: Tune MapReduce Parallelism in Apache Pig Jobs

Thanks to Wuheng Luo, a Hadoop and big data architect at Sears Holdings, for the guest post below about Pig job-level performance tuning

Many factors can affect Apache Pig job performance in Apache Hadoop, including hardware, network I/O, cluster settings, code logic, and algorithm. Although the sysadmin team is responsible for monitoring many of these factors, there are other issues that MapReduce job owners or data application developers can help diagnose, tune, and improve. One such example is a disproportionate Map-to-Reduce ratio—that is, using too many reducers or mappers in a Pig job.

Pig is Flying: Apache Pig on Apache Spark

Our thanks to Mayur Rustagi (@mayur_rustagi), CTO at Sigmoid Analytics, for allowing us to re-publish his post about the Spork (Pig-on-Spark) project below. (Related: Read about the ongoing upstream to bring Spark-based data processing to Hive here.)

Analysts can talk about data insights all day (and night), but the reality is that 70% of all data analyst time goes into data processing and not analysis. At Sigmoid Analytics, we want to streamline this data processing pipeline so that analysts can truly focus on value generation and not data preparation.

How-to: Use Parquet with Impala, Hive, Pig, and MapReduce

The CDH software stack lets you use your tool of choice with the Parquet file format – - offering the benefits of columnar storage at each phase of data processing. 

An open source project co-founded by Twitter and Cloudera, Parquet was designed from the ground up as a state-of-the-art, general-purpose, columnar file format for the Apache Hadoop ecosystem. In particular, Parquet has several features that make it highly suited to use with Cloudera Impala for data warehouse-style operations:

How Wajam Answers Business Questions Faster With Hadoop

Thanks to Xavier Clements of Wajam for allowing us to re-publish his blog post about Wajam’s Hadoop experiences below!

Wajam is a social search engine that gives you access to the knowledge of your friends. We gather your friends’ recommendations from Facebook, Twitter, and other social platforms and serve these back to you on supported sites like Google, eBay, TripAdvisor, and Wikipedia.

Demo: Using Hue to Access Hive Data Through Pig

This installment of the Hue demo series is about accessing the Hive Metastore from Hue, as well as using HCatalog with Hue. (Hue, of course, is the open source Web UI that makes Apache Hadoop easier to use.) 

What is HCatalog?

HCatalog is a module in Apache Hive that enables non-Hive scripts to access Hive tables. You can then directly load tables with Apache Pig or MapReduce without having to worry about re-defining the input schemas, or caring about or duplicating the data’s location.

Make Hadoop Your Best Business Tool

Data analysts and business intelligence specialists have been at the heart of new trends driving business growth over the past decade, including log file and social media analytics. However, Big Data heretofore has been beyond the reach of analysts because traditional tools like relational databases don’t scale, and scalable systems like Apache Hadoop have historically required Java expertise. 

Demo: Apache Pig Editor in Hue 2.3

In the previous installment of the demo series about Hue — the open source Web UI that makes Apache Hadoop easier to use — you learned how to analyze data with Hue using Apache Hive via Hue’s Beeswax and Catalog applications. In this installment, we’ll focus on using the new editor for Apache Pig in Hue 2.3.

Complementing the editors for Hive and Cloudera Impala, the Pig editor provides a great starting point for exploration and real-time interaction with Hadoop. This new application lets you edit and run Pig scripts interactively in an editor tailored for a great user experience. Features include:

What’s New in Hue 2.3

We’re very happy to announce the 2.3 release of Hue, the open source Web UI that makes Apache Hadoop easier to use.

Hue 2.3 comes only two months after 2.2 but contains more than 100 improvements and fixes. In particular, two new apps were added (including an Apache Pig editor) and the query editors are now easier to use.

How Persado Supports Persuasion Marketing Technology with Data Analyst Training

This guest post comes from Alex Giamas, Senior Software Engineer on the data warehouse team at Persado, an ultra-hot persuasion marketing technology company with operations in Athens, Greece.

A World-Class EDW Requires a World-Class Hadoop Team

Persado is the global leader in persuasion marketing technology, a new category in digital marketing. Our revolutionary technology maps the genome of marketing language and generates the messages that work best for any customer and any product at any time. To assure the highest quality experience for both our clients and end-users, our engineering team collaborates with Ph.D. statisticians and data analysts to develop new ways to segment audiences, discover content, and deliver the most relevant and effective marketing messages in real time.

How To: Use Oozie Shell and Java Actions

Apache Oozie, the workflow coordinator for Apache Hadoop, has actions for running MapReduce, Apache Hive, Apache Pig, Apache Sqoop, and Distcp jobs; it also has a Shell action and a Java action. These last two actions allow us to execute any arbitrary shell command or Java code, respectively.

In this blog post, we’ll look at an example use case and see how to use both the Shell and Java actions in more detail. Please follow along below; you can get a copy of the full project at Cloudera’s GitHub as well. This how-to assumes some basic familiarity with Oozie.

Example Use Case

Apache Hadoop Developer Training Helps Query Massive Telecom Data

This guest post is provided by Rohit Menon, Product Support and Development Specialist at Subex.

I am a software developer in Denver and have been working with C#, Java, and Ruby on Rails for the past six years. Writing code is a big part of my life, so I constantly keep an eye out for new advances, developments, and opportunities in the field, particularly those that promise to have a significant impact on software engineering and the industries that rely on it. 

In my current role working on revenue assurance products in the telecom space for Subex, I have regularly heard from customers that their data is growing at tremendous rates and becoming increasingly difficulty to process, often forcing them to portion out data into small, more manageable subsets. The more I heard about this problem, the more I realized that the current approach is not a solution, but an opportunity, since companies could clearly benefit from more affordable and flexible ways to store data. Better query capability on larger data sets at any given time also seemed key to derive the rich, valuable information that helps drive business. Ultimately, I was hoping to find a platform on which my customers could process all their data whenever they needed to. As I delved into this Big Data problem of managing and analyzing at mega-scale, it did not take long before I discovered Apache Hadoop.

Mission: Hands-On Hadoop

Apache Pig: It Goes to 0.11

This blog was originally published at blog.apache.org/pig and is republished here for your convenience by permission of its author, Pig Committer Dmitriy Ryaboy.

After months of work, we are happy to announce the 0.11 release of Apache Pig. In this blog post, we highlight some of the major new features and performance improvements that were contributed to this release. A large chunk of the new features was created by Google Summer of Code (GSoC) students with supervision from the Apache Pig PMC, while the core Pig team focused on performance improvements, usability issues, and bug fixes. We encourage CS students to consider applying for GSOC in 2013 – it’s a great way to contribute to open source software.

Save 15% on Multi-Course Public Training Enrollments in January and February

Cloudera University is the world leader in Apache Hadoop training and certification. Our full suite of live courses and online materials is the best resource to get started with your Hadoop cluster in development or advance it towards production.  We offer deep industry insight into the skills and expertise required to establish yourself as a leading Developer or Administrator managing and processing Big Data in this fast-growing field.

But did you know Cloudera training can also help you plan for the advanced stages and progress of your Hadoop cluster? In addition to core training for Developers and Administrators, we also offer the best (and, in some cases, only) opportunity to get up to speed on lifecycle projects within the Hadoop ecosystem in a classroom setting. Cloudera University’s course offerings go beyond the basics to include Training for Apache HBase, Training for Apache Hive and Pig, and Introduction to Data Science: Building Recommender Systems. Depending on your Big Data agenda, Cloudera training can help you increase the accessibility and queryability of your data, push your data performance towards real-time, conduct business-critical analyses using familiar scripting languages, build new applications and customer-facing products, and conduct data experiments to improve your overall productivity and profitability.

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.

The New "Hadoop in Practice" Book: A Chat with The Author

Today we bring you a brief interview with Alex Holmes, author of the new book, Hadoop in Practice (Manning). You can learn more about the book and download a free sample chapter here.

There are a few good Hadoop books on the market right now. Why did you decide to write this book, and how is it complementary to them?
When I started working with Hadoop I leaned heavily on Tom White’s excellent book, Hadoop: The Definitive Guide (O’Reilly Media), to learn about MapReduce and how the internals of Hadoop worked. As my experience grew and I started working with Hadoop in production environments I had to figure out how to solve problems such as moving data in and out of Hadoop, using compression without destroying data locality, performing advanced joining techniques and so on. These items didn’t have a lot of coverage in existing Hadoop books, and that’s really the idea behind Hadoop in Practice – it’s a collection of real-world recipes that I learned the hard way over the years.

What’s New in CDH4.1 Pig

Apache Pig is a platform for analyzing large data sets that provides a high-level language called Pig Latin. Pig users can write complex data analysis programs in an intuitive and compact manner using Pig Latin.

Among many other enhancements, CDH4.1, the newest release of Cloudera’s open-source Hadoop distro, upgrades Pig from version 0.9 to version 0.10. This post provides a summary of the top seven new features introduced in CDH4.1 Pig.

Boolean Data Type

Applying Parallel Prediction to Big Data

This guest post is provided by Dan McClary, Principal Product Manager for Big Data and Hadoop at Oracle.

One of the constants in discussions around Big Data is the desire for richer analytics and models. However, for those who don’t have a deep background in statistics or machine learning, it can be difficult to know not only just what techniques to apply, but on what data to apply them. Moreover, how can we leverage the power of Apache Hadoop to effectively operationalize the model-building process? In this post we’re going to take a look at a simple approach for applying well-known machine learning approaches to our big datasets. We’ll use Pig and Hadoop to quickly parallelize a standalone machine-learning program written in Jython.

Playing Weatherman

CDH4.1 Now Released!

Update time!  As a reminder, Cloudera releases major versions of CDH, our 100% open source distribution of Apache Hadoop and related projects, annually and then updates to CDH every three months.  Updates primarily comprise bug fixes but we will also add enhancements.  We only include fixes or enhancements in updates that maintain compatibility, improve system stability and still allow customers and users to skip updates as they see fit.

We’re pleased to announce the availability of CDH4.1.  We’ve seen excellent adoption of CDH4.0 since it went GA at the end of June and a number of exciting use cases have moved to production.  CDH4.1 is an update that has a number of fixes but also a number of useful enhancements.  Among them:

What Do Real-Life Apache Hadoop Workloads Look Like?

Organizations in diverse industries have adopted Apache Hadoop-based systems for large-scale data processing. As a leading force in Hadoop development with customers in half of the Fortune 50 companies, Cloudera is in a unique position to characterize and compare real-life Hadoop workloads. Such insights are essential as developers, data scientists, and decision makers reflect on current use cases to anticipate technology trends.

Recently we collaborated with researchers at UC Berkeley to collect and analyze a set of Hadoop traces. These traces come from Cloudera customers in e-commerce, telecommunications, media, and retail (Table 1). Here I will explain a subset of the observations, and the thoughts they triggered about challenges and opportunities in the Hadoop ecosystem, both present and in the future.

Process a Million Songs with Apache Pig

The following is a guest post kindly offered by Adam Kawa, a 26-year old Hadoop developer from Warsaw, Poland. This post was originally published in a slightly different form at his blog, Hakuna MapData!

Recently I have found an interesting dataset, called Million Song Dataset (MSD), which contains detailed acoustic and contextual data about a million songs. For each song we can find information like title, hotness, tempo, duration, danceability, and loudness as well as artist name, popularity, localization (latitude and longitude pair), and many other things. There are no music files included here, but the links to MP3 song previews at 7digital.com can be easily constructed from the data.

Cloudera Software Engineer Eli Collins on Apache Hadoop and CDH4

In June 2012, Eli Collins (@elicollins), from Cloudera’s Platforms team, led a session at QCon New York 2012 on the subject “Introducing Apache Hadoop: The Modern Data Operating System.” During the conference, the QCon team had an opportunity to interview Eli about several topics, including important things to know about CDH4, main differences between MapReduce 1.0 and 2.0, Hadoop use cases, and more. It’s a great primer for people who are relatively new to Hadoop.

You can catch the full interview (video and transcript versions) here.

CDH3 update 5 is now available

We are happy to announce the general availability of CDH3 update 5. This update is a maintenance release of CDH3 platform and provides a considerable amount of bug-fixes and stability enhancements. Alongside these fixes, we have also included a few new features, most notable of which are the following:

Using Apache Hadoop to Find Signal in the Noise: Analyzing Adverse Drug Events

Last month at the Web 2.0 Summit in San Francisco, Cloudera CEO Mike Olson presented some work the Cloudera Data Science Team did to analyze adverse drug events. We decided to share more detail about this project because it demonstrates how to use a variety of open-source tools – R, Gephi, and Cloudera’s Distribution Including Apache Hadoop (CDH) – to solve an old problem in a new way.

Background: Adverse Drug Events

An adverse drug event (ADE) is an unwanted or unintended reaction that results from the normal use of one or more medications. The consequences of ADEs range from mild allergic reactions to death, with one study estimating that 9.7% of adverse drug events lead to permanent disability. Another study showed that each patient who experiences an ADE remains hospitalized for an additional 1-5 days and costs the hospital up to $9,000.

Hadoop World 2011: A Glimpse into Development

The Development track at Hadoop World is a technical deep dive dedicated to discussion about Apache Hadoop and application development for Apache Hadoop. You will hear committers, contributors and expert users from various Hadoop projects discuss the finer points of building applications with Hadoop and the related ecosystem. The sessions will touch on foundational topics such as HDFS, HBase, Pig, Hive, Flume and other related technologies. In addition, speakers will address key development areas including tools, performance, bringing the stack together and testing the stack. Sessions in this track are for developers of all levels who want to learn more about upcoming features and enhancements, new tools, advanced techniques and best practices.

Preview of Development Track Sessions

New Features in Apache Pig 0.8

This is a guest post contributed by Dmitriy Ryaboy (@squarecog) and was originally published in his blog on December 19th. We thought the information was valuable enough that it was worth reposting to spread the word even further. 

Hadoop World: NYC – Training

Our vision for Hadoop World is a conference where both newcomers and experienced Hadoop users can learn and be part of the growing Hadoop community.

We are also offering training sessions for newcomers and experienced Hadoop users alike. Whether you are looking for an Introduction to Hadoop, Hadoop Certification, or you want to learn more about related Hadoop projects we have the training you are looking for.

Migrating to CDH

With the recent release of CDH3b2, many users are more interested than ever to try out Cloudera’s Distribution for Hadoop (CDH). One of the questions we often hear is, “what does it take to migrate?”.

Why Migrate?

If you’re not familiar with CDH3b2, here’s what you need to know.

Announcing Two New Training Classes from Cloudera: Introduction to HBase and Analyzing Data with Hive and Pig

Cloudera is pleased to announce two new training courses: a one-day Introduction to HBase and a two-day session on Analyzing Data with Hive and Pig. These join a recently-expanded two-day Hadoop for Administrators course and our popular three-day Hadoop for Developers offering, any of which can be combined to provide extensive, customized training for your organization. Please contact sales@cloudera.com for more information regarding on-site training, or visit www.cloudera.com/hadoop-training to view our public course schedule.

Cloudera’s HBase course discusses use-cases for HBase, and covers the HBase architecture, schema modeling, access patterns, and performance considerations. During hands-on exercises, students write code to access HBase from Java applications, and use the HBase shell to manipulate data. Introduction to HBase also covers deployment and advanced features.

What’s New in CDH3b2: Oozie

Hadoop has emerged as an indispensable component of any data-intensive enterprise infrastructure.  In many ways, working with large datasets on a distributed computing platform (powered by commodity hardware or cloud infrastructure) has never been easier. But because customers are running clusters consisting of hundreds or thousands of nodes, and are processing massive quantities of data from production systems every hour, the logistics of efficient platform utilization can quickly become overwhelming.

To deal with this challenge, the Yahoo! engineering team created Oozie – the Hadoop workflow engine. We are pleased to provide Oozie with Cloudera’s distribution for Hadoop starting with the beta-2 release.

Why create a new workflow system?

What’s New in CDH3b2: Pig

CDH3 beta 2 includes Apache Pig 0.7.0, the latest and greatest version of the popular dataflow programming environment for Hadoop. In this post I’ll review some of the bigger changes that went into Pig 0.7.0, describe the motivations behind these changes, and explain how they affect users. Readers in search of a canonical list of changes in this new version of Pig should consult the Pig 0.7.0 Release Notes as well as the list of backward incompatible changes.

Load-Store Redesign

The biggest change to appear in Pig 0.7.0 is the complete redesign of the LoadFunc and StoreFunc interfaces. The Load-Store interfaces were first introduced in version 0.1.0 and have remained largely unchanged up to this point. Pig uses a concrete instance of the LoadFunc interface to read Pig records from the underlying storage layer, and similarly uses an instance of the StoreFunc interface when it needs to write a record. Pig provides different LoadFunc and StoreFunc implementations in order to support different storage formats, and since this is a public interface users may provide their own implementations as well.

CDH3 Beta 1 Now Available

CDH2 is released

We’re proud to announce that Cloudera’s Distribution for Hadoop Version 2 (CDH2) is officially released.

We’ve come a long way to get to a production quality release. At the beginning of September we announced the first beta of CDH2. After 6 months of additional testing we announced a release candidate. The release candidate spent over a month hardening in Cloudera’s internal QA process and on a wide variety of customer clusters. CDH2 is now stable and ready for use – we are pleased to recommend it to all our production users.

CDH2: “Testing” Heading Towards “Stable”

In September 2009, we announced the first release of CDH2, our current testing repository. Packages in our testing repository are recommended for people who want more features and are willing to upgrade as bugs are worked out. Our testing packages pass unit and functional tests but will not have the same “soak time” as our stable packages. A testing release represents a work in progress that will eventually be promoted to stable. It’s a long road of feedback, bug fixes, QA and testing to move from testing to stable. As someone who tracks the maturity of a testing build throughout its life cycle, I’m pleased to say we’ve put a lot of polish into this release.
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CDH2: Testing Release now with Pig, Hive, and HBase

At the beginning of September, we announced the first release of CDH2, our current testing repository. Packages in our testing repository are recommended for people who want more features and are willing to upgrade as bugs are worked out. Our testing packages pass unit and functional tests but will not have the same “soak time” as our stable packages. A testing release represents a work in progress that will eventually be promoted to stable.

We plan on pushing new packages into the testing repository every 3 to 6 weeks.  And it just so happens it is just about 3 weeks after we announced the first testing release. So it must be time for a new one. Here are some of the highlights:

CDH2: Cloudera’s Distribution for Apache Hadoop 2

In March of this year, we released our distribution for Apache Hadoop.  Our initial focus was on stability and making Hadoop easy to install. This original distribution, now named CDH1, was based on the most stable version of Apache Hadoop at the time:0.18.3. We packaged up Apache Hadoop, Pig and Hive into RPMs and Debian packages to make managing Hadoop installations easier.  For the first time ever, Hadoop cluster managers were able to bring up a deployment by running one of the following commands depending on your Linux distribution:

Analyzing Apache logs with Apache Pig

(guest blog post by Dmitriy Ryaboy)

A number of organizations donate server space and bandwidth to the Apache Foundation; when you download Apache Hadoop, Tomcat, Maven, CouchDB, or any of the other great Apache projects, the bits are sent to you from a large list of mirrors. One of the ways in which Cloudera supports the open source community is to host such a mirror.

Apache Pig Training Now Available Online

Today I did a web search for “pig training” using my favorite search engine. I was wildly entertained by the results, and have embedded my favorite for your viewing pleasure.