SQL Denali - AlwaysOn

  • AlwaysON by design looks similar to database mirroring. Can some one comment on how the data being passing through different groups.Is it something like as DB mirroring in the form of tran log or any other technique?

  • As far as I've seen, Always on is a hybrid between Database Mirroring and Clustering. It uses Clustering to maintain Quorum, and Mirroring to replicate data between the nodes. Due to the clustering model in Windows Server 2008 and later, you don't need a shared disk since clustering can use MNS or MNS+Fileshare as quorum model, and database mirroring don't need shared storage.



    Ole Kristian Velstadbråten Bangås - Virinco - Facebook - Twitter

    Concatenating Row Values in Transact-SQL[/url]

  • Thank you for your reply.

    However I was about to ask a question like how AlwaysON will move the committed data from Primary to secondaries? Is this still based on transaction log shipping or any other new techniques.

  • Disclaimer: I've not tested this in a lab, only read about it.

    Each mirror (or seconadary if you want) can be set up to be updated synchronously or asynchronously. In addition, they can be configured for automatic failover or not.



    Ole Kristian Velstadbråten Bangås - Virinco - Facebook - Twitter

    Concatenating Row Values in Transact-SQL[/url]

  • I guess my question is not clear. Sorry for that.

    DBMirroring, the transactions are going from principal to mirroring through tran logs.

    How it is been handled in AlwaysON? I guess now the question is quite straight forward.Please let me know perhaps I can be more clear on the question.

  • Ah, I see now. It uses mirroring for replication, so it's the same.



    Ole Kristian Velstadbråten Bangås - Virinco - Facebook - Twitter

    Concatenating Row Values in Transact-SQL[/url]

Viewing 6 posts - 1 through 5 (of 5 total)

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