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How does Windows Server always on availability groups work?
Always On availability groups relies on the Windows Server Failover Cluster (WSFC) to monitor and manage the current roles of the availability replicas that belong to a given availability group and to determine how a failover event affects the availability replicas.
Do you need failover cluster for always on availability groups?
Deploying Always On availability groups requires a Windows Server Failover Cluster (WSFC). To be enabled for Always On availability groups, an instance of SQL Server must reside on a WSFC node, and the WSFC and node must be online. Furthermore, each availability replica of a given availability group must reside on a different node of the same WSFC.
What are the prerequisites for always on availability groups?
This article describes considerations for deploying Always On availability groups, including prerequisites, restrictions, and recommendations for host computers, Windows Server failover clusters (WSFC), server instances, and availability groups. For each of these components security considerations and required permissions, if any, are indicated.
How to set up AlwaysOn availability groups in SQL Server?
Kendra Little explains the differences between shared disk clustering and the AlwaysOn Availability Groups clustering. How to Set Up AlwaysOn Availability Groups – A screenshot tour showing a simple lab installation from start to finish.
What does it mean to support an availability group Listener?
Supports an availability group listener for each availability group. An availability group listener is a server name to which clients can connect in order to access a database in a primary or secondary replica of an Always On availability group.
How many databases can a availability group support?
An availability group supports a set of read-write primary databases and one to eight sets of corresponding secondary databases. Optionally, secondary databases can be made available for read-only access and/or some backup operations.
What are the components of the availability group?
Each availability group defines a set of two or more failover partners known as availability replicas. Availability replicas are components of the availability group. Each availability replica hosts a copy of the availability databases in the availability group.