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Mirroring TimeOut through VPN RRS feed

  • Question

  • Hi there,


    I have 2 issues with mirroring, The first problem is the Timeout (My Timeout is 60 seconds) and second one is the speed rate of the mirroring. I configured mirroring through a VPN to test the speed of the comunication because we are thinking to use it for DRP(Costa Rica to Panama). My big concern is the speed how the SQL sends the packages to the destination. For Example. My VPN can reach 9Megabits/sec of speed with a copy of files, but with the mirroring it can not take more than 1.5mbps . How can i improve this rate?.  also, we realized after we run the Index Maintenance  the Log grows at leas an extra 5GB and it hits the mirroring send rate over the VPN greatly (it adds hours). What can i do to handle the index mantenance in a database with mirroring configured?.


    I appreciate any help or guide that you can give us.



    My Software: Windows Server 2003 R2, SP2,SQL 2005  SP3

    Wednesday, April 1, 2009 6:40 PM

All replies

  • One thing that you need to consider when implementing DR solutions like database mirroring or log shipping is the amount of growth your transaction logs will have, including tasks like index maintenance as this will definitely increase your log. Have you considered rewriting your index maintenance to only defragment indexes greater than a certain value defined in your sys.dm_db_index_physical_stats?

    Check out this whitepaper on Database Mirroring Best Practices and performance considerations
    http://technet.microsoft.com/en-us/library/cc917681.aspx


    bass_player http://bassplayerdoc.blogspot.com/
    Friday, April 3, 2009 10:35 PM
  • I already checked the Whitepaper, thank for your replay.  With the index the big problem is that one table is enough to affect greatly the Mirroring performance. I can not understand why this process must affect the performance if the Mirroring is recommended for DRP solution (I know the index maintenance is a log process, but event that is  stupid for me its add this load to the process). Why the index proces just only sends the commands to do the maintenance in the mirroring server. It could be better???.

    Monday, April 6, 2009 2:32 PM
  • If you are using SQL Server 2008, taking advantage of the new log stream compression could help you, but you still need to take into account things like index maintenance. The index rebuild is logged in both places essentially; it's not just being applied to the mirror. Otherwise the t-log wouldn't be functioning properly, nor would mirroring.

    I agree that chunking up your maintenance to help your D/R plans may help, but this is the way it should be working.
    Allan Hirt Blog: http://www.sqlha.com/blog Author: Pro SQL Server 2008 Failover Clustering (Apress - due out June, 2009)
    Monday, April 6, 2009 5:29 PM