Another SQL Server 2012 AlwaysOn paper from the cats at sqlCat... &quot;Building a High Availability and Disaster Recovery Solution by Using Failover Cluster Instances and Availability Groups&quot;

Wednesday, July 04, 2012

Another SQL Server 2012 AlwaysOn paper from the cats at sqlCat... "Building a High Availability and Disaster Recovery Solution by Using Failover Cluster Instances and Availability Groups"

sqlCat - Whitepapers - AlwaysOn Architecture Guide: Building a High Availability and Disaster Recovery Solution by Using Failover Cluster Instances and Availability Groups

SQL Server 2012 AlwaysOn Failover Cluster Instances (FCI) and AlwaysOn Availability Groups provide a comprehensive high availability and disaster recovery solution. Prior to SQL Server 2012, many customers used FCIs to provide local high availability within a data center and database mirroring for disaster recovery to a remote data center. With SQL Server 2012, this design pattern can be replaced with an architecture that uses FCIs for high availability and availability groups for disaster recovery business requirements. Availability groups leverage Windows Server Failover Clustering (WSFC) functionality and enable multiple features not available in database mirroring. This paper details the key topology requirements of this specific design pattern, including asymmetric storage considerations, quorum model selection, quorum votes, steps required to build the environment, and a workflow illustrating how to handle a disaster recovery event in the new topology across participating job roles.

Also of note: SQL Server 2012 AlwaysOn High Availability and Disaster Recovery Design Patterns

SQL Server 2012 AlwaysOn provides flexible design choices for selecting an appropriate high availability and disaster recovery solution for your application. SQL Server AlwaysOn was developed for applications that require high uptime, need protection against failures within a data center (high availability) and adequate redundancy against data center failures (disaster recovery). http://msdn.microsoft.com/en-us/sqlserver/gg490638 provides an overview of high availability and disaster recovery solutions available in SQL Server 2012 AlwaysOn.

Through working with customers who are evaluating and deploying SQL Server 2012 AlwaysOn currently, we have seen the following design patterns emerge as end-to-end HA+DR solution:

Using Multi-site Failover Cluster Instance (FCI) for local high availability and disaster recovery solution

Using Availability Groups (AG) for local high availability and disaster recovery solution

Using Failover Cluster Instance (FCI) for local high availability, and Availability Groups (AG) for disaster recovery solution

We expect most of the SQL Server 2012 AlwaysOn deployments to match one of these design patterns or contain slight variations.

So, how do these three design patterns compare and contrast? This blog highlights the salient features of each of these design patterns. A detailed whitepaper on each of these will be developed and published in near future.

Multi-site Failover Cluster Instance (FCI) for HA and DR

Availability Group for HA and DR

Failover Cluster Instance for local HA and Availability Group for DR