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Why is StartCopyFromBlob timing out on me? RRS feed

  • Question

  • i thought this was supposed to be asynchronous. what is going on? i have only a small window to copy a 500gb vhd from one storage account to another.

    Wednesday, September 19, 2012 11:34 PM

Answers

  • Hi,

    >>when stepping through the code, the debugger never stepped past the call to StartCopyFromBlob() as one would expect from an asynchronous call

    The copy operation will be asynchronous, but as REST interface requires an HTTP request, the HTTP request-response to start the copy operation will be synchronous, and the operatio will continue to run after the response has been sent back. If, for some reason, the HTTP request times out iI'd guess that the method call will block.

    Are other operations agains the same service account working OK?

    Regards,

    Alan


    Free EBook: "Windows Azure Service Bus Developer Guide" http://www.cloudcasts.net/devguide/

    Thursday, September 27, 2012 1:38 PM

All replies

  • Copy blob is indeed asynchronous. Can you describe the error in more detail? Did Windows Azure accepted the process and then it timed out or you got the error little bit later.

    Thursday, September 20, 2012 3:58 AM
  • when stepping through the code, the debugger never stepped past the call to StartCopyFromBlob() as one would expect from an asynchronous call. interestingly, the copy process actually did execute in azure. since i had no idea it was actually happening, i tried running my program again. after i ran my program the 2nd time, which also resulted in a time out, i saw that the vhd showed up in the target storage account. unfortunately, by that time, the 2nd copy process already started and i had to wait some time before i could use the vhd.
    Friday, September 21, 2012 4:49 AM
  • Hi - when was your destination storage account created, and what library are you using to send the command (sounds like maybe Client library 1.7.1, but I want to make sure).

    Thanks!


    -Jeff

    Friday, September 21, 2012 8:11 PM
  • yes, it's version 1.7.1 from github. the source storage account was created in july. the destination storage account was created in august.

    Monday, September 24, 2012 9:24 AM
  • So the operation succeeds, but the client library is behaving abnormally. If you use the library shipped with the latest SDK instead of the library in github, what is the result? The libraries may be somewhat different.
    Thursday, September 27, 2012 1:33 PM
  • Hi,

    >>when stepping through the code, the debugger never stepped past the call to StartCopyFromBlob() as one would expect from an asynchronous call

    The copy operation will be asynchronous, but as REST interface requires an HTTP request, the HTTP request-response to start the copy operation will be synchronous, and the operatio will continue to run after the response has been sent back. If, for some reason, the HTTP request times out iI'd guess that the method call will block.

    Are other operations agains the same service account working OK?

    Regards,

    Alan


    Free EBook: "Windows Azure Service Bus Developer Guide" http://www.cloudcasts.net/devguide/

    Thursday, September 27, 2012 1:38 PM
  • Yes, Alan is correct - StartCopyFromBlob begins the asynchronous copy blob operation.  However, it does make the REST call before returning, so it's not a true asynchronous method in the .net sense.  So the real question is what Alan said - do other operations work correctly?

    -Jeff


    -Jeff

    Monday, October 1, 2012 4:21 PM