The main difference between Always On and failover cluster
is the level at which they provide high availability and disaster
recovery:
Always On
Provides high availability and disaster
recovery at the SQL database level. Always On availability groups (AAG) do
not require shared storage.
Failover cluster
Provides high availability for applications
and services by using a group of independent servers. If one server fails,
another server in the cluster can take over its workload. Failover
clusters require some form of shared storage.
Here are some other differences between Always On and failover
cluster:
How they work
Always On failover cluster instances (FCIs)
work on the server-instance level, while failover clusters work on the server
level.
How they use shared storage
FCIs require shared storage, while AAGs do
not.
How they handle failover
FCIs use Windows Server Failover Clustering
(WSFC) to handle failover, while AAGs have replication settings.
How they provide remote disaster recovery
FCIs can use AAGs to provide remote disaster
recovery at the database level.
No comments:
Post a Comment