Book Image

Professional Azure SQL Database Administration - Second Edition

By : Ahmad Osama
Book Image

Professional Azure SQL Database Administration - Second Edition

By: Ahmad Osama

Overview of this book

Despite being the cloud version of SQL Server, Azure SQL Database differs in key ways when it comes to management, maintenance, and administration. This book shows you how to administer Azure SQL Database to fully benefit from its wide range of features and functionalities. Professional Azure SQL Database Administration begins by covering the architecture and explaining the difference between Azure SQL Database and the on-premise SQL Server to help you get comfortable with Azure SQL Database. You’ll perform common tasks such as migrating, backing up and restoring a SQL Server database to an Azure database. As you progress, you’ll understand how you can reduce costs, and manage and scale multiple SQL databases using elastic pools. You’ll also implement a disaster recovery solution using standard and active geo-replication. Whether it is learning different techniques to monitor and tune an Azure SQL Database or improving performance using in-memory technology, this book will enable you to make the most out of Azure SQL database features and functionality for data management solutions. By the end of this book, you’ll be well-versed with key aspects of an Azure SQL Database instance, such as migration, backup restorations, performance optimization, high availability, and disaster recovery.
Table of Contents (11 chapters)

High Availability

High availability refers to providing business continuity when the physical server hosting Azure SQL Database fails.

As discussed in Lesson 1, Microsoft Azure SQL Database Primer, Azure SQL Database is hosted on three servers – one primary server and two secondary servers:

Figure 8.1: Azure SQL Database is hosted on three servers

The toyfactory database consists of three servers: one primary server and at least two secondary servers. The Azure SQL Server is just a logical server name used for connections. When an application sends a connection request, the gateway finds the current primary server and routes the request to it.

The primary and secondary servers are within the same data center and together form a quorum set.

All reads and writes are made to the primary server. Azure SQL Database uses a quorum-based commit method that makes sure that the data is hardened at the primary server and replicated to at least one secondary server before the transaction...