Chapter 25
AlwaysOn Availability Groups
WHAT’S IN THIS CHAPTER
- Identifying All Aspects of Availability Groups and Mastering All their Intricacies
- Researching Hardware and Software Configurations to Identify What Works Best for Your Organization
- Configuring Hardware and then Clustering the Operating System
- Configuring SQL Server 2012 Availability Groups
- Administering and Troubleshooting the Production SQL Server 2012 Availability Group
- Testing, Monitoring and Tuning for Performance
- Documenting
An Availability Group is a new feature part of AlwaysOn in SQL Server 2012 that delivers robust high-availability enhancements that greatly improve the data mirroring capabilities that shipped starting with SQL Server 2005. With AlwaysOn, SQL Server 2012 implements Availability Groups that deliver similar capabilities to database mirroring. In addition to these key enhancements, it can support up to five replica partners, multiple databases in a single group, and readable replica secondary servers. The primary and replica servers can be mixed in asynchronous/synchronous modes and do not require shared disks; as a result they can deploy across different geographical locations. When these databases have dependencies, they can be grouped in a single Availability Group to failover together as a single failover unit. By supporting readable replica servers, for example, reporting or read-only workload can be offloaded to a secondary replica, reducing the load onto the primary replica where it ...
