Would it be possible to change the Azure Blob Storage API version?

[rachtsingh]

Hello,

I'm accessing ECMWF real-time open data hosted for example at this url: https://ai4edataeuwest.blob.core.windows.net/ecmwf/20240201/06z/0p25/scda/20240201060000-6h-scda-fc.grib2. However, it looks like HEAD requests to that URL tell me that the server doesn't accept HTTP range requests:

{
    "Access-Control-Allow-Origin": "*",
    "Access-Control-Expose-Headers": "x-ms-request-id,Server,x-ms-version,Content-Type,Last-Modified,ETag,Content-MD5,x-ms-lease-status,x-ms-blob-type,Content-Length,Date,Transfer-Encoding",
    "Content-Length": "63162417",
    "Content-MD5": "qqfa7u8ezDERRAnR1WD1Zw==",
    "Content-Type": "application/octet-stream",
    "Date": "Tue, 24 Sep 2024 21:19:36 GMT",
    "ETag": "0x8DC2323E4CAFF28",
    "Last-Modified": "Thu, 01 Feb 2024 12:47:04 GMT",
    "Server": "Windows-Azure-Blob/1.0 Microsoft-HTTPAPI/2.0",
    "x-ms-blob-type": "BlockBlob",
    "x-ms-lease-status": "unlocked",
    "x-ms-request-id": "0cb1b60d-801e-0017-6bc7-0e5979000000",
    "x-ms-version": "2009-09-19"
}

(it should say Accept-Ranges: bytes). As mentioned on the Planetary Computer page the index files are published to allow reading a subset of the data (and HTTP range requests are the easiest way).

I think the issue is "x-ms-version", which indicates that this is using a pretty old blob storage API version. Based on this Github issue I think fixing it should be pretty quick, though I'm not aware of any costs of changing (my uninformed guess is that it should be low since Azure recommends using the latest version).

In the meantime I'll download the full .grib files and then subset them on device, but I wanted to flag this since it'll save everyone a lot of bandwidth.

[rachtsingh]

Actually, the server gave me the correct range when I made a GET request later, so it looks like range requests are supported. Feel free to close if Accept-Ranges: bytes isn't meant to be returned.

[srijan55]

Since the actual range request works, closing this.

[Bukharee]

I finally got it to return Accept-Ranges: bytes after hours in rabbit holes

honestly sometimes i find it hard to even justify why someone at Microsoft will make such a shitty decision

good for you @rachtsingh you don't have to get the header to stream, but for me i'm using an external library and the function doesn't care it checks for that header first before it attempts streaming, but the only api service version that supports returning that header starts at 2018, and microsoft by default when you create a bucket even in 2025 they assign a default api service version to 2009!, why who knows but it doesn't make sense, you have to change the version i couldn't find it in the ui but i found a command to change here it is

az storage account blob-service-properties update
--resource-group
--account-name
--default-service-version 2023-01-03

make sure to edit the command and add you actual and