Post reply

logic/algorithm behind mirroring?

  • May 12, 2010 at 10:46 am

    #146938

    Hello,

    can someone please explain me the logic/algorithm behind mirrroing..i am familiar with how it works and the setup...even though it doesnt really creates any jobs how are the data changes being transmitted?

  • May 12, 2010 at 11:14 am

    #1166400

    If I'm not mistaken, Data Mirroring uses the Service Broker to transmit data over to the mirror. So everything is queued up as messages that are read into the mirror. And that means, when the mirroring breaks, the messages are still queued until everything's reestablished and the SB just continues sending the messages like nothing ever happened.

    Someone please correct me if I'm wrong.

    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.

  • May 12, 2010 at 2:51 pm

    #1166541

    Service Broker is part of the answer, that's why you don't see any jobs. The other part is that it is essentially reading the logs and using that to determine what goes to the mirror. So DB Mirroring is like a hybrid or Replication and log shipping. That is until you use syncronous mirroring when it gets a bit more involved.

    Leo

    Leo
    Nothing in life is ever so complicated that with a little work it can't be made more complicated.

  • May 13, 2010 at 8:48 am

    #1166944

    thanks leo and brandie for the response..

    Leo:

    You said it reads the log...which process reads? do you mean ldf's are read?thanks..

Viewing 4 posts - 1 through 3 (of 3 total)

You must be logged in to reply to this topic. Login to reply