Home Forums SQL Server 2012 SQL 2012 - General Always ON SQL Server 2012 RE: Always ON SQL Server 2012

  • August 8, 2014 at 4:02 am

    #1736349

    Firstly, have a look at this.

    http://msdn.microsoft.com/en-gb/library/ff878716.aspx

    Libby1981 (8/7/2014)

    Hello:The question I have is about the third node that I plan on adding to this cluster.

    The third node dbprod1c will be in a different site and will be setup for asynchronous replication. The question I have is around configuring the listener service and understanding how failover takes place during a real DR situation.

    Scenario ---

    Nodes a and b are on the same site and therefore on the same subnet (example: 10.2.0.x). The listener service is on the same subnet as the two nodes.

    Node c is in a different site and therefore on another subnet (example: 10.4.0.x).

    Note that all systems will be on the same VLAN.

    I can easily add node c to the Windows FC.

    What do I need to do to add it to the database availability group? How should the listener be configured or does it matter? Are applications connecting to the "listener"?

    You can either utilise a single IP address within the VLAN that all 3 nodes will be connected to, with SQL server 2012 on however, you are also able to use multiple subnet IPs instead. If you look at the network name resource in a cluster group and go to the dependencies tab, you'll see you have the option to select multiple IP resources and then set the name resource to require all IPs online or a single IP online, this is all detailed in the link i posted above. Have a good look at it and do some testing then post back if you're stuck

    Libby1981 (8/7/2014)

    What will happen if my primary site fails and the link between the two sites is down? Should the application be configured to connect to read-only copy and connect to the endpoint in secondary site directly?

    I would like some tips on inter-site failover during real DR situation. We have web/app servers that will need to connect to these databases and uptime is crucial.

    Please advise.

    Thanks,

    Geeta

    Have you given thought to what quorum configuration you'll use when the 3rd node is added, will you want the 3rd node on the DR site to have a vote and potentially influence cluster behaviour?

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

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