Category Archives: Guest

How-to: Tune MapReduce Parallelism in Apache Pig Jobs

Categories: Guest How-to Pig

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,

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How-to: Scan Salted Apache HBase Tables with Region-Specific Key Ranges in MapReduce

Categories: Guest HBase How-to

Thanks to Pengyu Wang, software developer at FINRA, for permission to republish this post.

Salted Apache HBase tables with pre-split is a proven effective HBase solution to provide uniform workload distribution across RegionServers and prevent hot spots during bulk writes. In this design, a row key is made with a logical key plus salt at the beginning. One way of generating salt is by calculating n (number of regions) modulo on the hash code of the logical row key (date,

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Graduating Apache Parquet

Categories: Guest Parquet

The following post from Julien Le Dem, a tech lead at Twitter, originally appeared in the Twitter Engineering Blog. We bring it to you here for your convenience.

ASF, the Apache Software Foundation, recently announced the graduation of Apache Parquet, a columnar storage format for the Apache Hadoop ecosystem. At Twitter, we’re excited to be a founding member of the project.

Apache Parquet is built to work across programming languages,

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How-to: Get Started with CDH on OpenStack with Sahara

Categories: Cloud Guest

The recent OpenStack Kilo release adds many features to the Sahara project, which provides a simple means of provisioning an Apache Hadoop (or Spark) cluster on top of OpenStack. This how-to, from Intel Software Engineer Wei Ting Chen, explains how to use the Sahara CDH plugin with this new release.

Prerequisites

This how-to assumes that OpenStack is already installed. If not, we recommend using Devstack to build a test OpenStack environment in a short time.

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Scan Improvements in Apache HBase 1.1.0

Categories: Guest HBase

The following post, from Cloudera intern Jonathan Lawlor, originally appeared in the Apache Software Foundation’s blog.

Over the past few months there have a been a variety of nice changes made to scanners in Apache HBase. This post focuses on two such changes, namely RPC chunking (HBASE-11544) and scanner heartbeat messages (HBASE-13090). Both of these changes address long standing issues in the client-server scan protocol.

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