Book Image

Professional SQL Server High Availability and Disaster Recovery

By : Ahmad Osama
Book Image

Professional SQL Server High Availability and Disaster Recovery

By: Ahmad Osama

Overview of this book

Professional SQL Server High Availability and Disaster Recovery explains the high availability and disaster recovery technologies available in SQL Server: Replication, AlwaysOn, and Log Shipping. You’ll learn what they are, how to monitor them, and how to troubleshoot any related problems. You will be introduced to the availability groups of AlwaysOn and learn how to configure them to extend your database mirroring. Through this book, you will be able to explore the technical implementations of high availability and disaster recovery technologies that you can use when you create a highly available infrastructure, including hybrid topologies. Note that this course does not cover SQL Server Failover Cluster Installation with shared storage. By the end of the book, you’ll be equipped with all that you need to know to develop robust and high performance infrastructure.
Table of Contents (9 chapters)
Professional SQL Server High Availability and Disaster Recovery
Preface

AlwaysOn Availability Group Concepts and Terminology


An AlwaysOn availability group is a group of databases that can fail over from a primary server to a secondary server automatically or manually, as and when required. Commonly known as AlwaysOn AGs, they're the premium high availability and disaster recovery solution available in SQL Server.

Other than being an HA and a DR solution, it can also be used to load-balance read workloads, for maintenance jobs such as backups, and for consistency checks on the secondary databases.

Availability Groups Concepts and Components

A typical AlwaysOn AG topology is shown in the following diagram:

Figure 4.1: Example of an AlwaysOn topology

The given AlwaysOn implementation consists of three replicas or nodes: Primary Replica, Secondary Replica 1, and Secondary Replica 2. The three nodes are part of the same domain name and the same Windows Server Failover Cluster.

An AlwaysOn AG consists of the following components.

Windows Server Failover Cluster

A Windows...