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Log Generation Rate RRS feed

  • Question

  •  Hi,
     
    We have to calculate the required network bandwidth for synchronous mirroring with high availability on a WAN, i got some threads wherein it was mentioned that bandwidth has to be three times the log generation rate. My question is how to calculate a the log generation rate per minute or second of a DB. Any answers are highly appreciated.

    Regards
    Rojit



    Apps Dev
    Tuesday, January 13, 2009 10:11 AM

All replies

  • The 3 to one ratio is a good place to start your benchmarking. The easiest way to look at the transaction log generation rate in my opinion is to look at the transaction log history and size of files produced in the actual production system that you plan to mirror.

    Then you can physically test the bandwidth by actually copying some large transaction log files using robocopy to test the actual bandwidth you get on that connection, to ensure it meets the 3:1 ratio, as opposed to just looking at the theroetical spec of the connection.

    If you don't have a production system yet, then you could run a volume test on your test / development system and look at the amount of log produced there. There's no real way to theoretically calculate the size of log that will be produced by a given server because it will be completely dependent upon the nature of the application and its transaction throughput.

    Graham Kent [MSFT]
    SQL Server Support Escalation Engineer
    http://blogs.msdn.com/grahamk

    All postings are provided "AS IS" with no warranties, and confers no rights



    • Proposed as answer by globalgoat Tuesday, February 21, 2012 1:01 PM
    Thursday, January 15, 2009 12:17 PM