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Slow package with ASYNC_NETWORK_IO wait, despite all datasources on local server

  • October 12, 2012 at 7:49 am

    #147433

    I have a package thats doing a lot of work and taking a long time to run.

    I think its taking longer than necessary though.

    When i check the sql server wait types i see two in particular, in this order:

    ASYNC_NETWORK_IO

    PREEMPTIVE_OS_WAITFORSINGLEOBJECT

    When i check the most recent wait type on the session for the ssis package the last wait type is usually

    PREEMPTIVE_OS_WAITFORSINGLEOBJECT

    Package is running on the server and all data sources are on the same server so everything is local.

    There is latency from the server to my pc ( US to Europe) but that shouldnt matter when kicking the package off on the server.

    Any advice would be great.

    Thanks!

  • October 12, 2012 at 8:58 am

    #1548703

    Async network IO, despite it's name, seldom has anything to do with network. It's a wait mainly from the client being slow to accept the resultset

    Gail Shaw
    Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
    SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

    We walk in the dark places no others will enter
    We stand on the bridge and no one may pass

  • October 12, 2012 at 10:11 am

    #1548754

    Thanks Gail. Makes sense.

    Turns out that despite the VM being allocated 2.3Ghz of processing power its only getting on average 500Mhz. Something else on the host has priority on the CPU pool.

    The package can pull the source data quicker than it can process it and put it into the warehouse, which would agree with your description of the general cause of Async Network IO.

    Will sort the CPU first anyway and try again after that.

    Thanks!

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