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In 3 seconds around 15 transacions comes.

  • October 19, 2011 at 12:31 am

    #259005

    I have a sql sevrer cluster and for 3 seconds it takes in movement to another node.

    In thses 3 seconds around 15 transacions comes.

    Please answer:

    1.Will these 15 transactions will be lost during cluster movement?

    2. The 100 connections which are already created with database will they also disconnect?

    Thanks

  • October 19, 2011 at 1:12 am

    #1396477

    1. Those 15 transactions will not be performed. SQL server will refuse any connection during that time.

    2. I think they will be disconnected.

    Ryan
    //All our dreams can come true, if we have the courage to pursue them//

  • October 19, 2011 at 2:19 am

    #1396499

    The instance will go into shutdown and not accept any new connections during the fail over. Any connections which are currently running at the point of failure will terminate. If the transaction is complete it will get replayed upon startup when recovery is started if not it will roll forward / rollback the database to a consistant state.

    That is my understanding

  • October 19, 2011 at 3:19 am

    #1396513

    You could mitigate against this by writing a try/catch into the application code, parsing feedback from SQL Server for 'SQLServerException', 'Connection refused' or similar. You could alter it so that if such a message is received, the transaction is retried after x seconds (i.e. 5 seconds).

    Maybe easier said than done, yes - but it means that if a CONNECT is attempted during failover, there's an automatic reattempt. If an exception is raised by SQL Server because e.g. the transaction was rolled back midway during failover, it is resubmitted.

    Depends on what high-availability, high-transactional, hardcore application is running on there and what requirements it has.

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