Synchronize Files to Azure blob

Question

Hi,
I have download the samples from http://code.msdn.microsoft.com/Release/ProjectReleases.aspx?ProjectName=sync&ReleaseId=3638 I was able to upload files from filesystem to Azure blob however the download says "creating file... but i dont see any files created in the targetted directory.  Initially it was error at FileRetreiver.cs as shown below

 

public string AbsoluteSourceFilePath

{

 

get

{

 

throw new NotImplementedException("Absolute Path Not Supported");

}

}

I change this code to return the path but file is not created.  Am i missing anything?

It will be nice if you guys create New root level category like SyncFx-AzureSynchronization.

Thanks.

Answer 1

It works only if i set the value of RelativePath to Empty.  I also noticed that Delete method leads to concurrency violation hence i modified to
blob.Delete(opts); --Leads to concurrency violation
blob.DeleteIfExists();--Does the delete without error.

Not sure why but it works.

Thanks.

Answer 2

"Delete method leads to concurrency violation"

Do you mean in AzureBlobStore.cs @ line 373 (in DeleteFile)?

// Specify an optimistic concurrency check to prevent races with other endpoints syncing at the same time.
BlobRequestOptions opts = new BlobRequestOptions();
opts.AccessCondition = AccessCondition.IfNotModifiedSince(expectedLastModified);

try
{
       blob.Delete(opts);
}

The problem is that the ListBlobs request is not bringing back the LastModified DateTime, so the AccessCondition is never met and you get a violation.

So DeleteIfExists just works because it doesn't check the concurrency condition.

To fix this (and probably other issues) add a call to FetchAttributes to the ListBlobs method in AzureBlobStore.cs:

foreach (IListBlobItem o in Container.ListBlobs(opts))
{
    CloudBlob blob = Container.GetBlobReference(o.Uri.ToString());
    blob.FetchAttributes(); // Add this line to ensure that attributes are enumerated
    ItemFieldDictionary dict = new ItemFieldDictionary();