Comment 10 for bug 1934849

Yeah, I put the same config on purpose for both s3 and swift. But tweaking large_object_size didn't make any difference.

[swift]
large_object_size = 5120
large_object_chunk_size = 200

[s3]
s3_store_large_object_size = 5120
s3_store_large_object_chunk_size = 200

After digging into the actual environment, it seems image_size is always zero so this condition never goes to multipart upload, but singlepart upload always.
https://opendev.org/openstack/glance_store/src/branch/stable/ussuri/glance_store/_drivers/s3.py#L597

I guess Glance will never know the actual image_size at the beginning of getting image data from a client until getting all of the data. I just don't know what kind of cases we will get non-null value in "size".
https://docs.openstack.org/api-ref/image/v2/index.html?expanded=create-image-detail#create-image