Cloudera Developer Blog · Pig Posts
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.
Hadoop in Practice covers more advanced aspects of working with Hadoop such as MapReduce and HDFS patterns, performance tuning and debugging. The book also looks at how Hadoop can be used as a platform for data science and for data warehousing by studying R integration techniques, and intermediary Pig and Hive recipes. Data mining is another important topic today, and a book on Hadoop isn’t complete without a look at how Mahout lets you run your favorite algorithms at scale.
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
Pig Latin is continuously evolving. As with other actively developed programming languages, more data types are being added to Pig. CDH4.1 adds the boolean type. The boolean type is internally mapped to the Java Boolean class, and the boolean constants ‘TRUE’ and ‘FALSE’ are case-insensitive. Here are some example uses of boolean type:
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.
I’d like to predict the weather. Heck, we all would – there’s personal and business value in knowing the likelihood of sun, rain, or snow. Do I need an umbrella? Can I sell more umbrellas? Better yet, groups like the National Climatic Data Center offer public access to weather data stretching back to the 1930s. I’ve got a question I want to answer and some big data with which to do it. On first reaction, because I want to do machine learning on data stored in HDFS, I might be tempted to reach for a massively scalable machine learning library like Mahout.
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:
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.
Table 1. Summary of Hadoop workloads analyzed
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.
The dataset consists of 339 tab-separated text files. Each file contains about 3,000 songs and each song is represented as one separate line of text. The dataset is publicly available and you can find it at Infochimps or Amazon S3. Since the total size of this data sums up to around 218GB, processing it using one machine may take a very long time.
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.
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:
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.
Some adverse drug events are caused by drug interactions, where two or more prescription or over-the-counter (OTC) drugs taken together leads to an unexpected outcome. As the population ages and more patients are treated for multiple health conditions, the risk of ADEs from drug interactions increases. In the United States, roughly 4% of adults older than 55 are at risk for a major drug interaction.
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.
Building Web Analytics Processing on Hadoop at CBS Interactive
Michael Sun, CBS Interactive