The S3 specification says that versions are ordered in the response of
list object versions.
mc snapshot needs this to know which version comes first especially when
two versions have the same exact last-modified field.
Looking into full disk errors on zoned setup. We don't take the
5% space requirement into account when selecting a zone.
The interesting part is that even considering this we don't
know the size of the object the user wants to upload when
they do multipart uploads.
It seems quite defensive to always upload multiparts to
the zone where there is the most space since all load will
be directed to a part of the cluster.
In these cases we make sure it can at least hold a 1GiB file
and we disadvantage fuller zones more by subtracting the
expected size before weighing.
This PR fixes all the below scenarios
and handles them correctly.
- existing data/bucket is replaced with
new content, no versioning enabled old
structure vanishes.
- existing data/bucket - enable versioning
before uploading any data, once versioning
enabled upload new content, old content
is preserved.
- suspend versioning on the bucket again, now
upload content again the old content is purged
since that is the default "null" version.
Additionally sync data after xl.json -> xl.meta
rename(), to avoid any surprises if there is a
crash during this rename operation.
- Implement a new xl.json 2.0.0 format to support,
this moves the entire marshaling logic to POSIX
layer, top layer always consumes a common FileInfo
construct which simplifies the metadata reads.
- Implement list object versions
- Migrate to siphash from crchash for new deployments
for object placements.
Fixes#2111
Anis Elleuch
Klaus Post
Harshavardhana