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Time for an automatic Failover in a DAG RRS feed

  • Question

  • Hi all,

    I just set up my first DAG. I want to test the funcionallity of it. When i simulate an error like stopping the Exchange Informationsstorage Service on one Server the second Server does correctly mount the copy of the database. But it takes about 4 minutes.

    Is that normal? Is there a possibility to reduce the time?

    greetings, swissjunior

    Saturday, April 30, 2011 6:08 PM

Answers

  • Hi all,

    I just set up my first DAG. I want to test the funcionallity of it. When i simulate an error like stopping the Exchange Informationsstorage Service on one Server the second Server does correctly mount the copy of the database. But it takes about 4 minutes.

    Is that normal? Is there a possibility to reduce the time?

    greetings, swissjunior


    How long does it take if you reboot a server or activate a store on another server?

    There is no automatic activation if the administrator stops the IS:

    http://technet.microsoft.com/en-us/library/dd298067.aspx

    Switchovers and Failovers
    • Proposed as answer by Tony MurrayMVP Sunday, May 1, 2011 3:42 AM
    • Marked as answer by swissjunior Sunday, May 1, 2011 5:59 PM
    Saturday, April 30, 2011 10:57 PM

All replies

  • Hi all,

    I just set up my first DAG. I want to test the funcionallity of it. When i simulate an error like stopping the Exchange Informationsstorage Service on one Server the second Server does correctly mount the copy of the database. But it takes about 4 minutes.

    Is that normal? Is there a possibility to reduce the time?

    greetings, swissjunior


    How long does it take if you reboot a server or activate a store on another server?

    There is no automatic activation if the administrator stops the IS:

    http://technet.microsoft.com/en-us/library/dd298067.aspx

    Switchovers and Failovers
    • Proposed as answer by Tony MurrayMVP Sunday, May 1, 2011 3:42 AM
    • Marked as answer by swissjunior Sunday, May 1, 2011 5:59 PM
    Saturday, April 30, 2011 10:57 PM
  • In my experience an automatic failover takes only a few seconds.

    Have a look through the Application event log on both servers and see if there is anything unusual.


    Tony www.activedir.org blog:www.open-a-socket.com
    Sunday, May 1, 2011 3:44 AM
  • 1. Monitor your DAG.  There's some scripts supplied (CollectOverMetrics.ps1,CollectReplicationMetrics.ps1,CheckDatabaseRedundancy.ps1 ) .  There's a number of options/switces you can use.  Some of the scripts collect data during and after a failover/switchover.  Some verbose options available. 

    http://technet.microsoft.com/en-us/library/dd351258.aspx#CollectOver

    2. Test normal switchover at database level, then at server level (controlled by you) issue still the same

    3. To test failover, I would not stop the IS, instead, disable the network card(s) on one memeber and test.

    4. Although stopping the IS may take 4 mins, This will not trigger a auto failover, try killing the process via taskmgr instead. See KB article above.

    Sukh

     


    Sunday, May 1, 2011 3:41 PM
  • IF you want to test disabling a NIC, then it must be the NIC used for the MAPI network. Disabling the Replication NIC will not cause a failover.

     

    Sunday, May 1, 2011 4:24 PM
  • thanks for the overview... that's what i'm looking for. i'll test other scenarios including disabling the network interfaces.

     

    Sunday, May 1, 2011 6:01 PM