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AlwaysOn with two Nodes (1+1) between two Sites. Idiotic? RRS feed

  • Question

  • I want a (light) HA/DR solution.. 

    Users works via VPN that is connected to a Datacenter (Primary site) where all servers are located. Its [B]very, very[/B] crucial that the Users can access the Database even if their Internet is down at their company (Secondary site). If the Primary site goes down, it will Automatic Failover to the Secondary site (where Users are working).

    Is AlwaysOn the best solution here, and where should I place the File witness. I don't want the cluster to go offline on me. :-) I have checked out Replication, it seems flaky..

    I have SQL 2016 Standard license, and can use two SQL servers. I know its not much..


    Tuesday, June 14, 2016 2:39 AM

Answers

  • Hi abborre,

    In this case, it seems a 2 node failover cluster isn’t an option as it require a shared storage between nodes. With SQL Server 2016 Standard edition, you could have a 2 node Basic Availability Group running over your sites. It’s a limited version of Availability Group and it’s only available in Standard Edition. The Limitations are:
    1. It only supports 2 replicas(Primary/Secondary).
    2. It only supports one availability database.
    3. Backup and read operation are not supported on secondary database.

    To allow automatic failover in Basic Availability Group, these conditions has to be satisfied:
    1. WSFC Quorum has to be satisfied. In your case if you plan to use file share quorum, it should be placed in secondary site.
    2. Synchronous mode settings on primary replica and secondary replica should be both in synchronous-commit mode to allow automatic failover.
    3. Automatic Failover settings on primary replica and secondary replica should be both enabled to allow automatic failover.
    4. The synchronization state on secondary replica should be ‘Synchronized’ to allow automatic failover.

    In addition, if you require more than one availability databases in your availability group, you may consider use SQL Server Enterprise edition instead. You can also have multiple Basic Availability Groups each hosting a single availability database.

    For more information, please refer to MSDN article.

    If you have any other questions, please let me know.

    Regards,
    Lin

    Wednesday, June 15, 2016 4:40 AM