Entries in Hadoop (20)


Hadoop and Salesforce Integration: the Ultimate Successful Database Merger  

How we can transfer salesforce data to hadoop? It is big challenge to everyday users. What are different features of data transfer tools.

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Hypertable Routs HBase in Performance Test -- HBase Overwhelmed by Garbage Collection

This is a guest post by Doug Judd, original creator of Hypertable and the CEO of Hypertable, Inc.

Hypertable delivers 2X better throughput in most tests -- HBase fails 41 and 167 billion record insert tests, overwhelmed by garbage collection -- Both systems deliver similar results for random read uniform test

We recently conducted a test comparing the performance of Hypertable (@hypertable) version to that of HBase (@HBase) version 0.90.4 (CDH3u2) running Zookeeper 3.3.4.  In this post, we summarize the results and offer explanations for the discrepancies. For the full test report, see Hypertable vs. HBase II.


Hypertable and HBase are both open source, scalable databases modeled after Google's proprietary Bigtable database.  The primary difference between the two systems is that Hypertable is written in C++, while HBase is written in Java.  We modeled this test after the one described in section 7 of the Bigtable paper and tuned both systems for maximum performance.  The test was run on a total of sixteen machines connected together with gigabit Ethernet.  The machines had the following configuration:

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Making Hadoop 1000x Faster for Graph Problems

Dr. Daniel Abadi, author of the DBMS Musings blog and Cofounder of Hadapt, which offers a product improving Hadoop performance by 50x on relational data, is now taking his talents to graph data in Hadoop's tremendous inefficiency on graph data management (and how to avoid it), which shares the secrets of getting Hadoop to perform 1000x better on graph data.


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Map-Reduce With Ruby Using Hadoop

Map-Reduce With Hadoop Using Ruby A demonstration, with repeatable steps, of how to quickly fire-up a Hadoop cluster on Amazon EC2, load data onto the HDFS (Hadoop Distributed File-System), write map-reduce scripts in Ruby and use them to run a map-reduce job on your Hadoop cluster. You will not need to ssh into the cluster, as all tasks are run from your local machine. Below I am using my MacBook Pro as my local machine, but the steps I have provided should be reproducible on other platforms running bash and Java.


Twitter’s Plan to Analyze 100 Billion Tweets

If Twitter is the “nervous system of the web” as some people think, then what is the brain that makes sense of all those signals (tweets) from the nervous system? That brain is the Twitter Analytics System and Kevin Weil, as Analytics Lead at Twitter, is the homunculus within in charge of figuring out what those over 100 billion tweets (approximately the number of neurons in the human brain) mean.

Twitter has only 10% of the expected 100 billion tweets now, but a good brain always plans ahead. Kevin gave a talk, Hadoop and Protocol Buffers at Twitter, at the Hadoop Meetup, explaining how Twitter plans to use all that data to an answer key business questions.

What type of questions is Twitter interested in answering? Questions that help them better understand Twitter. Questions like:

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Building a Data Intensive Web Application with Cloudera, Hadoop, Hive, Pig, and EC2

This tutorial will show you how to use Amazon EC2 and Cloudera's Distribution for Hadoop to run batch jobs for a data intensive web application.

During the tutorial, we will perform the following data processing steps.... read more on Cloudera website


Building a data cycle at LinkedIn with Hadoop and Project Voldemort

Update: Building Voldemort read-only stores with Hadoop.

A write up on what LinkedIn is doing to integrate large offline Hadoop data processing jobs with a fast, distributed online key-value storage system, Project Voldemort.


Yahoo! Distribution of Hadoop

Many people in the Apache Hadoop community have asked Yahoo! to publish the version of Apache Hadoop they test and deploy across their large Hadoop clusters. As a service to the Hadoop community, Yahoo is releasing the Yahoo! Distribution of Hadoop -- a source code distribution that is based entirely on code found in the Apache Hadoop project.

This source distribution includes code patches that they have added to improve the stability and performance of their clusters. In all cases, these patches have already been contributed back to Apache, but they may not yet be available in an Apache release of Hadoop.

Read more and get the Hadoop distribution from Yahoo


Hive - A Petabyte Scale Data Warehouse using Hadoop

This post about using Hive and Hadoop for analytics comes straight from Facebook engineers.

Scalable analysis on large data sets has been core to the functions of a number of teams at Facebook - both engineering and non-engineering. Apart from ad hoc analysis and business intelligence applications used by analysts across the company, a number of Facebook products are also based on analytics.

These products range from simple reporting applications like Insights for the Facebook Ad Network, to more advanced kind such as Facebook's Lexicon product.

As a result a flexible infrastructure that caters to the needs of these diverse applications and users and that also scales up in a cost effective manner with the ever increasing amounts of data being generated on Facebook, is critical. Hive and Hadoop are the technologies that we have used to address these requirements at Facebook.

Read the rest of the article on Engineering @ Facebook's Notes page


Product: Hadoop

Update 5: Hadoop Sorts a Petabyte in 16.25 Hours and a Terabyte in 62 Seconds and has its green cred questioned because it took 40 times the number of machines Greenplum used to do the same work. Update 4: Introduction to Pig. Pig allows you to skip programming Hadoop at the low map-reduce level. You don't have to know Java. Using the Pig Latin language, which is a scripting data flow language, you can think about your problem as a data flow program. 10 lines of Pig Latin = 200 lines of Java. Update 3: Scaling Hadoop to 4000 nodes at Yahoo!. 30,000 cores with nearly 16PB of raw disk; sorted 6TB of data completed in 37 minutes; 14,000 map tasks writes (reads) 360 MB (about 3 blocks) of data into a single file with a total of 5.04 TB for the whole job. Update 2: Hadoop Summit and Data-Intensive Computing Symposium Videos and Slides. Topics include: Pig, JAQL, Hbase, Hive, Data-Intensive Scalable Computing, Clouds and ManyCore: The Revolution, Simplicity and Complexity in Data Systems at Scale, Handling Large Datasets at Google: Current Systems and Future Directions, Mining the Web Graph. and Sherpa: Hosted Data Serving. Update: Kevin Burton points out Hadoop now has a blog and an introductory video staring Beyonce. Well, the Beyonce part isn't quite true. Hadoop is a framework for running applications on large clusters of commodity hardware using a computational paradigm named map/reduce, where the application is divided into many small fragments of work, each of which may be executed on any node in the cluster. It replicates much of Google's stack, but it's for the rest of us. Jeremy Zawodny has a wonderful overview of why Hadoop is important for large website builders: For the last several years, every company involved in building large web-scale systems has faced some of the same fundamental challenges. While nearly everyone agrees that the "divide-and-conquer using lots of cheap hardware" approach to breaking down large problems is the only way to scale, doing so is not easy. The underlying infrastructure has always been a challenge. You have to buy, power, install, and manage a lot of servers. Even if you use somebody else's commodity hardware, you still have to develop the software that'll do the divide-and-conquer work to keep them all busy It's hard work. And it needs to be commoditized, just like the hardware has been... Hadoop also provides a distributed file system that stores data on the compute nodes, providing very high aggregate bandwidth across the cluster. Both map/reduce and the distributed file system are designed so that node failures are automatically handled by the framework. Hadoop has been demonstrated on clusters with 2000 nodes. The current design target is 10,000 node clusters. The obvious question of the day is: should you build your website around Hadoop? I have no idea. There seems to be a few types of things you do with lots of data: process, transform, and serve. Yahoo literally has petabytes of log files, web pages, and other data they process. Process means to calculate on. That is: figure out affinity, categorization, popularity, click throughs, trends, search terms, and so on. Hadoop makes great sense for them for the same reasons it does Google. But does it make sense for your website? If you are YouTube and you have petabytes of media to serve, do you really need map/reduce? Maybe not, but the clustered file system is great. You get high bandwidth with the ability to transparently extend storage resources. Perfect for when you have lots of stuff to store. YouTube would seem like it could use a distributed job mechanism, like you can build with Amazon's services. With that you could create thumbnails, previews, transcode media files, and so on. When they have Hbase up and running that could really spike adoption. Everyone needs to store structured data in a scalable, reliable, highly performing data store. That's an exciting prospect for me. I can't wait for experience reports about "normal" people, familiar with a completely different paradigm, adopting this infrastructure. I wonder what animal O'Reilly will use on their Hadoop cover?

See Also

  • Open Source Distributed Computing: Yahoo's Hadoop Support by Jeremy Zawodny
  • Yahoo!'s bet on Hadoop by Tim O'Reilly
  • Hadoop Presentations
  • Running Hadoop MapReduce on Amazon EC2 and Amazon S3

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