SQL Server Clustering and Failover Cluster Instance

Copper Contributor

Hi Buddies,

 

I need a clarity on whether Clustering in SQL Server and Always on Failover Clustering Instance in SQL server are same or not. If not, kindly share some notes for both.

 

Thanks in advance.

4 Replies

Hi @csk9178,

 

Could you be more precise abt. your question? 

 

If you would like to know if Fail Cluster Instance (FCI) and Always On Availability Groups are the Same, then the Answer is no.

 

AVG are desasterrecovery mechanisms on DB-Level

FCI are on Instance lvl

 

You can combine both of them, with adding FCI on top of AVG. More Details are placed here: Failover cluster instance with availability groups - SQL Server Always On | Microsoft Learn

 

Cheers

 

Hi @DuersinKurt,

Thanks for your response. I am aware of Always On Failover Cluster Instance (FCI) and Always On Availability Group (AG) are different concepts.

My doubt here is whether Clustering in SQL Server and Always On Failover Cluster Instance (FCI) are same or different.
Initially I thought the calling names are different but both concepts are same. But still some confusion is here.

Kindly clarify.

Hi @csk9178

 

w/o being that deep into the full technical specification yes, they are the same thing. you are assuming correctly.

 

As part of the SQL Server Always On offering, Always On Failover Cluster Instances leverages Windows Server Failover Clustering (WSFC) functionality to provide local high availability through redundancy at the server-instance level-a failover cluster instance (FCI).

Always On failover cluster instances - SQL Server Always On | Microsoft Learn

 

 

Hi @DuersinKurt ,

 

Thanks for clarifying.