Issue with parallel uploads to the same blob

[M0dEx]

There seems to be an issue when 2 instances of this file system write to the same blob from 2 different processes in parallel, where one of the uploads fails with:

Azure error

    File "/code/.venv/lib/python3.10/site-packages/our_package/connector/storage/blob.py", line 117, in _save
        with self._fs.open(
    File "/code/.venv/lib/python3.10/site-packages/fsspec/spec.py", line 1963, in __exit__
        self.close()
    File "/code/.venv/lib/python3.10/site-packages/adlfs/spec.py", line 1908, in close
        super().close()
    File "/code/.venv/lib/python3.10/site-packages/fsspec/spec.py", line 1930, in close
        self.flush(force=True)
    File "/code/.venv/lib/python3.10/site-packages/fsspec/spec.py", line 1801, in flush
        if self._upload_chunk(final=force) is not False:
    File "/code/.venv/lib/python3.10/site-packages/fsspec/asyn.py", line 118, in wrapper
        return sync(self.loop, func, *args, **kwargs)
    File "/code/.venv/lib/python3.10/site-packages/fsspec/asyn.py", line 103, in sync
        raise return_result
    File "/code/.venv/lib/python3.10/site-packages/fsspec/asyn.py", line 56, in _runner
        result[0] = await coro
    File "/code/.venv/lib/python3.10/site-packages/adlfs/spec.py", line 2068, in _async_upload_chunk
        await bc.commit_block_list(
    File "/code/.venv/lib/python3.10/site-packages/azure/core/tracing/decorator_async.py", line 77, in wrapper_use_tracer
        return await func(*args, **kwargs)
    File "/code/.venv/lib/python3.10/site-packages/azure/storage/blob/aio/_blob_client_async.py", line 1861, in commit_block_list
        process_storage_error(error)
    File "/code/.venv/lib/python3.10/site-packages/azure/storage/blob/_shared/response_handlers.py", line 184, in process_storage_error
        exec("raise error from None")   # pylint: disable=exec-used # nosec
    File "<string>", line 1, in <module>
    
azure.core.exceptions.HttpResponseError: The specified block list is invalid.
RequestId:<request_id>
Time:2024-02-13T12:15:05.1957595Z
ErrorCode:InvalidBlockList
Content: <?xml version="1.0" encoding="utf-8"?><Error><Code>InvalidBlockList</Code><Message>The specified block list is invalid.

From our limited investigation, this seems to likely be caused by the way AzureBlobFile calculates the IDs of the uploaded blocks: https://github.com/fsspec/adlfs/blob/576fb7a6a53a55375b4458c09e5bb571d945d410/adlfs/spec.py#L2102-L2103

Could this be changed to a hash of the content or something similar, which would correspond to the actual contents of the uploaded block?

[cmp0xff]

Hi, it seems to me that we can do this:

• from hashlib import shake_128, and in class AzureBlobFile, create

    def _block_id(self, block_list: list[str] | None = None):
        if block_list is None:
            block_list = self._block_list
  
        return shake_128(str(block_list).encode()).hexdigest(4)[:-1]
  

• In https://github.com/fsspec/adlfs/blob/576fb7a6a53a55375b4458c09e5bb571d945d410/adlfs/spec.py#L2102-L2103

        block_id = self._block_id()
  

• In https://github.com/fsspec/adlfs/blob/576fb7a6a53a55375b4458c09e5bb571d945d410/adlfs/spec.py#L2116-L2117

                        block_id = self._block_id()
  

• In https://github.com/fsspec/adlfs/blob/576fb7a6a53a55375b4458c09e5bb571d945d410/adlfs/spec.py#L2132

                if block_id == self._block_id([]) and length == 0 and final:
  

[cmp0xff]

Now that the current #462 has been fixed, we would like to ask for a new release of adlfs, so that the changes can be applied. Maybe @TomAugspurger, since you have published the recent versions? Thanks.

[martindurant]

@TomAugspurger , you can dd me to the pypi project, if you want me to do it.

[TomAugspurger]

It should be automated through GitHub Actions on tags.

On Nov 14, 2024, at 8:28 AM, Martin Durant @.***> wrote:

@TomAugspurger https://github.com/TomAugspurger , you can dd me to the pypi project, if you want me to do it.

— Reply to this email directly, view it on GitHub https://github.com/fsspec/adlfs/issues/462#issuecomment-2476495565, or unsubscribe https://github.com/notifications/unsubscribe-auth/AAKAOIVQQLGXRZ4UROB2CTD2ASXQRAVCNFSM6AAAAABEFFI4K2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDINZWGQ4TKNJWGU. You are receiving this because you were mentioned.

[martindurant]

OK, then the docs at https://github.com/fsspec/adlfs/blob/main/CONTRIBUTING.md#release are outdated :)

[cmp0xff]

Hi, may I ask for an update on the version bump?

[martindurant]

Planning on it next week.

[cmp0xff]

Sorry for asking again, but may I ask for an update on the version bump? Thanks.