Combining AlwaysOn Groups With Failover Cluster Instances

  • JakDBA

    SSCommitted

    Points: 1610

    Hello,

    Was a very good blog explaining the very basic and standard features and ways to setup AO ,

    BUT how does the automated failover happens which is a inbuilt feature of AO ( HA) ,

    @JayMunnangi

  • venkatesh.srinivasan

    Grasshopper

    Points: 10

    But in the article http://www.sqlservercentral.com/articles/FCI/92196

    the SQL FCI ( Node3 and Node4) does not have identical filepaths as the Node1 and Node2 which are standalone

    The SQL FCI is installed on G:, H: and L:

    How does this demonstrate the Microsoft recommendation of having identical filepath ?

    I am looking at implementing this architecture but with both the SQL FCI and the standalone instances using the same drive letters .

    Any pointers would be much appreciated?

  • venkatesh.srinivasan

    Grasshopper

    Points: 10

    But in the article http://www.sqlservercentral.com/articles/FCI/92196

    the SQL FCI ( Node3 and Node4) does not have identical filepaths as the Node1 and Node2 which are standalone

    The SQL FCI is installed on G:, H: and L:

    How does this demonstrate the Microsoft recommendation of having identical filepath ?

    I am looking at implementing this architecture but with both the SQL FCI and the standalone instances using the same drive letters .

    Any pointers would be much appreciated?

  • Ashif Shaikh

    Default port

    Points: 1445

    Can we use always on AG with active/active SQL clusters, in which one FCI is the primary and the other one secondary replica?

    and what will happen if one of the nodes fails and both the instances run's on the same node?

    Any input will be appreciated.

  • Perry Whittle

    SSC Guru

    Points: 233859

    Ashif Shaikh (10/2/2015)


    Can we use always on AG with active/active SQL clusters, in which one FCI is the primary and the other one secondary replica?

    and what will happen if one of the nodes fails and both the instances run's on the same node?

    you would be unable to deploy the AG in the very first place with this configuration. This would fail the pre reqs check

    -----------------------------------------------------------------------------------------------------------

    "Ya can't make an omelette without breaking just a few eggs" 😉

  • keeyu2

    Old Hand

    Points: 389

    Has anyone able to add FCI and standalone to an AG? I am getting sql server error 19405 - If one replica is failover cluster instance, remove the overlapped node from its possible owners and try again.

  • Brandie Tarvin

    SSC Guru

    Points: 172757

    keeyu2 (10/13/2016)


    Has anyone able to add FCI and standalone to an AG? I am getting sql server error 19405 - If one replica is failover cluster instance, remove the overlapped node from its possible owners and try again.

    We have a cross-datacenter cluster (4 nodes). Node 1 & 2 on datacenter A (DCA) and Node 3 & 4 on datacenter B (DCB). Nodes 1 & 3 have an FCI and a standalone instance (the AG is on the standalone instance). Nodes 2 & 4 have a standalone instance for the other half of the AG.

    Node 1 has a primary AG group that does secondary on nodes 2, 3, and 4. Node 2 has a primary AG group that does secondary on nodes 1, 3, and 4. Nodes 3 and 4 are failover only so do not have anything but secondary AGs and are our secondary DR for the FCI.

    AFAIK you can't put the AGs on the FCI. They must be on the standalone instances only. Our FCIs are for other clustered databases that are not part of the AGs.

    Brandie Tarvin, MCITP Database AdministratorLiveJournal Blog: http://brandietarvin.livejournal.com/[/url]On LinkedIn!, Google+, and Twitter.Freelance Writer: ShadowrunLatchkeys: Nevermore, Latchkeys: The Bootleg War, and Latchkeys: Roscoes in the Night are now available on Nook and Kindle.

  • salkasalka

    SSC Veteran

    Points: 272

    AFAIK you can't put the AGs on the FCI. They must be on the standalone instances only.

    how could you say that? :w00t:

    you can have AOAG between two FCI or between FCI and standalone, only thing is you cannot have is automatic failover in such config

    (all servers must be part of same OS cluster)

  • keeyu2

    Old Hand

    Points: 389

    My environment is not as complicated. I have one FCI in one data center and want to replicate it to another datacenter using AG.

  • Brandie Tarvin

    SSC Guru

    Points: 172757

    keeyu2 (10/14/2016)


    My environment is not as complicated. I have one FCI in one data center and want to replicate it to another datacenter using AG.

    Then you need to have two different IPs, one for each data center (if you don't already) and then add them both to the AG.

    EDIT: The second server with the standalone instance MUST have Windows Clustering on it. AGs require OS clustering.

    Brandie Tarvin, MCITP Database AdministratorLiveJournal Blog: http://brandietarvin.livejournal.com/[/url]On LinkedIn!, Google+, and Twitter.Freelance Writer: ShadowrunLatchkeys: Nevermore, Latchkeys: The Bootleg War, and Latchkeys: Roscoes in the Night are now available on Nook and Kindle.

  • keeyu2

    Old Hand

    Points: 389

    It does. That is why i am confused.

  • Hikmer

    Old Hand

    Points: 392

    After struggling with a Failover Cluster combined with using Always On availability and having lots of problems, I would advise everyone to avoid using this as an architectural design. Had nothing bit problems getting things to actually fail over and Microsoft could not figure out the problem. You are just adding a layer of complexity that is begging for long hours of support if something actually goes wrong.

  • keeyu2

    Old Hand

    Points: 389

    That was the point for us to get enterprise for the second datacenter. From the technet article I have been reading if you do two FCI it is a lot easier because WSFC doesn't get confused vs. a stand alone server.

  • salkasalka

    SSC Veteran

    Points: 272

    guys, there is nothing to be confused of, I have this working and it's easy to replicate in lab as well. You are just making some mistake in configuring. and please stop spreading rumors and telling people what is not working and (supposedly) even Microsoft doesn't know. Misleading is often worse than telling "sorry I don't know"

  • keeyu2

    Old Hand

    Points: 389

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