Types of Cluster in SQL Server
Clustering is a collection of two or more physical servers or nodes, connected via a LAN, each of which hosts a SQL server instance and has the same access to shared storage. It provides high availability and protection from disasters whenever a server hosting the SQL Server instance fails. It is very useful to reduce the load on a particular server.
Types of Cluster in SQL:
There are mainly four types of clustering in SQL Server:
1. Single-instance Cluster: It is the most common and widely used architecture for configuring SQL Server clusters. In this type of clustering, there is only a single node that is active or holds a resource like SQL Server services in running mode, it is called Single-instance Clustering.
2. Multi-instance Cluster: In this type of clustering, there can be more than one node failover. It means that in case of failure, there can be more than one node actively available to take over the ownership of the resources.
3. Multi-site Cluster: In this type of clustering, there are two sites at physically dispersed locations or sites or data centers. If there is damage or failure at one site, the other will be up and running. It provides a much more robust solution and has high availability.
4. Guest Cluster: In this type of clustering, it may have the cluster nodes on the same physical server, although it is recommended that you configure cluster nodes on different physical servers.