Database can't be in two Availablity Groups

  • I been trying to learn availability groups since I have not implemented it.

    From my understanding you can have more than one group.

    Lets pretend we have two groups in one instance:

    1. Accounting

    2. Engineering

    From my understanding you can't make a database in two AG because it wouldn't make sense.

    But lets pretending there is one database that both are used by accounting and engineering.

    Would you have to make a third AG for future fail overs so that other databases in the other two group don't failover when not needed because when you fail over an AG all the databases inside it fail over.

    Thanks

  • It depends.

    Well, probably not. The fact that you do not want this new database, and one of the groups to not fail over seems to imply that the new database should be part of that group. Does your DR planning include a scenario where only the Engineering building gets swallowed by a rogue black hole that leaves the accountants alone?

    If the availability group does failover, and all of the applications connecting to the databases in the group are .NET based, they should still be able to connect, if they have the MultiSubnetFailover attribute in their connection strings. With the exception of network latency, this could allow both groups to continue working, although one of them may be slower.

  • 1) Things you don't want to failover together should be in different AGs.

    2) Note also that you need to be on a certain build of .NET to be able to have that automatic failover. Not sure, but I think it is 4.something.

    Best,
    Kevin G. Boles
    SQL Server Consultant
    SQL MVP 2007-2012
    TheSQLGuru on googles mail service

  • smallmoney (6/30/2014)


    I been trying to learn availability groups since I have not implemented it.

    Check my article at these links for more info

    Part1[/url]

    Part2[/url]

    Part3[/url]

    Part4[/url]

    smallmoney (6/30/2014)


    From my understanding you can have more than one group.

    That is correct.

    smallmoney (6/30/2014)


    From my understanding you can't make a database in two AG

    That is also correct.

    smallmoney (6/30/2014)


    But lets pretending there is one database that both are used by accounting and engineering.

    Would you have to make a third AG

    Yes

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

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

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