How is AlwaysOn Availability Groups configured and what is the role of Windows Server Failover Cluster in this process?
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Answer from AI
AlwaysOn Availability Groups (AG) in SQL Server provide high availability and disaster recovery for databases. The setup involves several key steps:
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Creating a Windows Server Failover Cluster (WSFC) — this is the foundation for AG. WSFC provides server clustering, allowing servers to operate as a single unit and automatically fail over.
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Configuring SQL Server Instances on each cluster node.
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Creating an Availability Group with selected databases for replication.
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Configuring replicas — primary and secondary, with a choice of synchronization mode (synchronous or asynchronous).
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Setting up a Listener — a virtual network name through which clients connect to the AG.
The role of WSFC in this process is critical: it monitors the status of nodes and automatically switches roles in case of failures, ensuring continuous database operation in the AG. Without WSFC, AG cannot function, as the cluster manages coordination and node state management.