2,279 Articles

Selecting Failover Modes

Last Updated On : Wednesday, May 27, 2015Availability groups fail over at the availability-replica level. Failover involves another instance becoming the primary replica, with the original primary replica being demoted to become a secondary replica. AlwaysOn Availability Groups support three forms of failover: ■ Automatic failover This form of failover occurs without administrator intervention. No […]

Configuring Availability Modes

Last Updated On : Wednesday, May 27, 2015AlwaysOn Availability Groups support similar modes to database mirroring. The type of availability mode that is appropriate depends on data loss and transaction latency requirements. You configure availability modes on a per-availability replica basis. AlwaysOn Availability Groups support the following availability modes: ■ Asynchronous-commit mode This mode is […]

Meeting Availability Group Prerequisites

Last Updated On : Wednesday, May 27, 2015For production environments, only SQL Server 2012 Enterprise edition supports AlwaysOn Availability Groups. When planning the deployment of AlwaysOn Availability Groups, the host server must meet the following conditions: ■ Host servers cannot be domain controllers. ■ Each host server must be a participant node in a Windows […]

Performing Manual Failover

Last Updated On : Wednesday, May 27, 2015You can use the Failover Cluster Manager to perform failover of the cluster resource from one node to another. For example, to perform failover of the SQLCRG resource from SQL-C to SQL-D, perform the following steps: Open Failover Cluster Manager from the Administrative Tools menu. Click the SQLCRG […]

Multi-Subnet Failover Clustering

Last Updated On : Wednesday, May 27, 2015Multi-subnet failover clustering is a special configuration where each node in the failover cluster is located on a different TCP/IP subnet. A multi-subnet failover cluster does not use shared storage. When configuring a multi-subnet failover cluster, you must use another solution to replicate data between the instances on […]