Book Image

High Availability MySQL Cookbook

By : Alexander Davies
Book Image

High Availability MySQL Cookbook

By: Alexander Davies

Overview of this book

High Availability is something that all web sites hope to achieve, especially those that are linked to big companies.MySQL, an open source relational database management system (RDBMS), can be made highly available to protect from corruption, hardware failure, software crashes, and user error. Running a MySQL setup is quite simple. Things start getting complex when you start thinking about the best way to provide redundancy. There are a large number of techniques available to add 'redundancy' and 'high availability' to MySQL, but most are both poorly understood and documented.This book will provide you with recipes showing how to design, implement, and manage a MySQL Cluster and achieve high availability using MySQL replication, block level replication, shared storage, and the open source Global File System (GFS).This book covers all the major techniques available for increasing availability of your MySQL databases. It demonstrates how to design, implement, troubleshoot and manage a highly available MySQL setup using any one of several techniques, which are shown in different recipes. It is based on MySQL Cluster 7.0, MySQL (for non clustered recipes) 5.0.77, and CentOS / RedHat Enterprise Linux 5.3.The book starts by introducing MySQL Cluster as a technology and explaining how to set up a simple cluster. It will help you to master the options available for backing up and restoring a file in the MySQL Cluster. By following the practical examples in this book, you will learn how to manage the MySQL Cluster. Further, we will discuss some troubleshooting aspects of the MySQL Cluster.We also have a look at achieving high availability for MySQL databases with the techniques of MySQL Replication, block level replication, shared storage (a SAN or NAS), and DRBD.Finally, you will learn the principles of Performance tuning and tune MySQL database for optimal performance.
Table of Contents (17 chapters)
High Availability MySQL Cookbook
Credits
About the Author
About the Reviewers
Preface
Base Installation
Index

Disk-based tables


It is possible to configure the data nodes in a MySQL Cluster to store most of their data on disk rather than in RAM. This can be useful where the amount of data to be stored is impossible to store in RAM (for example, due to financial constraints). However, disk-based tables clearly have significantly reduced performance as compared to memory tables.

Note

Disk-based tables still store columns with indexes in RAM. Only columns without indexes are stored on disk. This can result in a large RAM requirement even for disk-based tables.

Getting ready

To configure disk-based tables, data nodes should have spare space on a high performance block device.

To configure disk-based tables, we must configure each data node with a set of two files as follows:

  • TABLESPACES—disk-based tables store their data in TABLESPACES, which are made up of one or more data files

  • Logfile groups—disk-based tables store their ndb data in a logfile group made up of one or more undo logfiles

Note

Disk-based tables...