Book Image

HBase Administration Cookbook

By : Yifeng Jiang
Book Image

HBase Administration Cookbook

By: Yifeng Jiang

Overview of this book

As an Open Source distributed big data store, HBase scales to billions of rows, with millions of columns and sits on top of the clusters of commodity machines. If you are looking for a way to store and access a huge amount of data in real-time, then look no further than HBase.HBase Administration Cookbook provides practical examples and simple step-by-step instructions for you to administrate HBase with ease. The recipes cover a wide range of processes for managing a fully distributed, highly available HBase cluster on the cloud. Working with such a huge amount of data means that an organized and manageable process is key and this book will help you to achieve that.The recipes in this practical cookbook start from setting up a fully distributed HBase cluster and moving data into it. You will learn how to use all of the tools for day-to-day administration tasks as well as for efficiently managing and monitoring the cluster to achieve the best performance possible. Understanding the relationship between Hadoop and HBase will allow you to get the best out of HBase so the book will show you how to set up Hadoop clusters, configure Hadoop to cooperate with HBase, and tune its performance.
Table of Contents (16 chapters)
HBase Administration Cookbook
Credits
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface

WAL tool—manually splitting and dumping WALs


An HBase edit will first be written to a region server's Write Ahead Log (WAL). After the log is written successfully, MemStore of the region server will be updated. As WAL is a sequence file on HDFS, it will be automatically replicated to the two other DataNode servers by default, so that a single region server crash will not cause a loss of the data stored on it.

As WAL is shared by all regions deployed on the region server, the WAL needs to first be split so that it can be replayed on each relative region, in order to recover from a region server crash. HBase handles region server failover automatically by using this algorithm.

HBase has a WAL tool providing manual WAL splitting and dumping facilities. We will describe how to use this tool in this recipe.

Getting ready

We will need to put some data into an HBase table to have HBase generate WAL files for our demonstration. Again, we will use the hly_temp table in this recipe. We will put the...