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Migrations fail with error: (407) Proxy Authentication Required RRS feed

  • Question

  • We have been testing the SharePoint Migration Tool for loading larger (>100Gb) data sets to a SharePoint Online site. Using the tool has been working well, but after attempting a larger upload (~200Gb) the uploader started producing failures and eventually stopped working for that upload. Multiple retries resulted in the same failures.

    The symptoms are that the migration tool works for a period of time, then it starts to fail, usually at the stage where it is transferring packages to Azure servers, but also in some cases when unpacking data to SharePoint Online. The logs report the error:
    "The transfer failed. ---> Microsoft.WindowsAzure.Storage.StorageException: The remote server returned an error: (407) Proxy Authentication Required."

    Research suggests that this may be a response to throttling of the data transfers from the SharePoint Online servers. Is there a way that the Migration Tool indicates that this may be the cause, or do we have to rely looking somewhere in SharePoint Online to determine if this is the cause?

    Another suggestion is that it may just be a timeout of some authentication proxy. We have noticed that restarting the migration tool and resuming the transfer does not resolve the issue immediately, however, if the transfer is restarted the next day (12-24 hours later), the transfer does proceed again for a period of time (but we haven't yet see a full completion of our 200Gb test migration).

    Any advice/assistance would be greatly appreciated.

    Snipet from log message:

    AggregateException when upload C:\xxxx.....dat to Azure Storage, exception message: System.AggregateException: One or more errors occurred. ---> Microsoft.WindowsAzure.Storage.DataMovement.TransferException: The transfer failed. ---> Microsoft.WindowsAzure.Storage.StorageException: The remote server returned an error: (407) Proxy Authentication Required. ---> System.Net.WebException: The remote server returned an error: (407) Proxy Authentication Required.

    Tuesday, February 5, 2019 4:18 AM

Answers

  • It appears that the proxy authentication request is from an internal proxy server. There are some existing proxy bypass rules in place, but it appears that some connections in the SharePoint Migration Tool aren't bypassing the proxy. Testing has shown that the upload to the Azure servers continues to work, but at some stage in the migration, a http connection is attempted which routes to our proxy and causes the authentication request. We are currently analysing traffic and determining if we can have additional bypasses in place.

    It would be useful to know what connections the SharePoint Migration Tool uses so we can isolate all of this traffic and create the necessary rules to allow the tool to operate.


    • Marked as answer by David ONeill Wednesday, March 6, 2019 3:30 AM
    Sunday, February 10, 2019 11:34 PM