The bottom line is delete markers are a nuisance,
most applications are not version aware and this
has simply complicated the version management.
AWS S3 gave an unnecessary complication overhead
for customers, they need to now manage these
markers by applying ILM settings and clean
them up on a regular basis.
To make matters worse all these delete markers
get replicated as well in a replicated setup,
requiring two ILM settings on each site.
This PR is an attempt to address this inferior
implementation by deviating MinIO towards an
idempotent delete marker implementation i.e
MinIO will never create any more than single
consecutive delete markers.
This significantly reduces operational overhead
by making versioning more useful for real data.
This is an S3 spec deviation for pragmatic reasons.
Spark/Hadoop workloads which use Hadoop MR
Committer v1/v2 algorithm upload objects to a
temporary prefix in a bucket. These objects are
'renamed' to a different prefix on Job commit.
Object storage admins are forced to configure
separate ILM policies to expire these objects
and their versions to reclaim space.
Our solution:
This can be avoided by simply marking objects
under these prefixes to be excluded from versioning,
as shown below. Consequently, these objects are
excluded from replication, and don't require ILM
policies to prune unnecessary versions.
- MinIO Extension to Bucket Version Configuration
```xml
<VersioningConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
<Status>Enabled</Status>
<ExcludeFolders>true</ExcludeFolders>
<ExcludedPrefixes>
<Prefix>app1-jobs/*/_temporary/</Prefix>
</ExcludedPrefixes>
<ExcludedPrefixes>
<Prefix>app2-jobs/*/__magic/</Prefix>
</ExcludedPrefixes>
<!-- .. up to 10 prefixes in all -->
</VersioningConfiguration>
```
Note: `ExcludeFolders` excludes all folders in a bucket
from versioning. This is required to prevent the parent
folders from accumulating delete markers, especially
those which are shared across spark workloads
spanning projects/teams.
- To enable version exclusion on a list of prefixes
```
mc version enable --excluded-prefixes "app1-jobs/*/_temporary/,app2-jobs/*/_magic," --exclude-prefix-marker myminio/test
```
The current code considers a pool with all root disks to be as part
of a testing environment even if there are other pools with mounted
disks. This will result to illegitimate writing in root disks.
Fix this by simplifing the logic: require MINIO_CI_CD in order to skip
root disk check.
data shards were wrong due to a healing bug
reported in #13803 mainly with unaligned object
sizes.
This PR is an attempt to automatically avoid
these shards, with available information about
the `xl.meta` and actually disk mtime.
Also adding an API to allow resyncing replication when
existing object replication is enabled and the remote target
is entirely lost. With the `mc replicate reset` command, the
objects that are eligible for replication as per the replication
config will be resynced to target if existing object replication
is enabled on the rule.
when bidirectional replication is set up.
If ReplicaModifications is enabled in the replication
configuration, sync metadata updates to source if
replication rules are met. By default, if this
configuration is unset, MinIO automatically sync's
metadata updates on replica back to the source.
This is a minor change to call out the new documentation and warn
users to change their bookmarks. Once we are ready to set up
some redirects, we can remove this page from Gluegun TOC.
in the case of active-active replication.
This PR also has the following changes:
- add docs on replication design
- fix corner case of completing versioned delete on a delete marker
when the target is down and `mc rm --vid` is performed repeatedly. Instead
the version should still be retained in the `PENDING|FAILED` state until
replication sync completes.
- remove `s3:Replication:OperationCompletedReplication` and
`s3:Replication:OperationFailedReplication` from ObjectCreated
events type
Synchronous replication can be enabled by setting the --sync
flag while adding a remote replication target.
This PR also adds proxying on GET/HEAD to another node in a
active-active replication setup in the event of a 404 on the current node.
X-Minio-Replication-Delete-Status header shows the
status of the replication of a permanent delete of a version.
All GETs are disallowed and return 405 on this object version.
In the case of replicating delete markers.
X-Minio-Replication-DeleteMarker-Status shows the status
of replication, and would similarly return 405.
Additionally, this PR adds reporting of delete marker event completion
and updates documentation
Delete marker replication is implemented for V2
configuration specified in AWS spec (though AWS
allows it only in the V1 configuration).
This PR also brings in a MinIO only extension of
replicating permanent deletes, i.e. deletes specifying
version id are replicated to target cluster.
Generalize replication target management so
that remote targets for a bucket can be
managed with ARNs. `mc admin bucket remote`
command will be used to manage targets.
