Refactor replication resync to be an active process (#14266)

When resync is triggered, walk the bucket namespace and
resync objects that are unreplicated. This PR also adds
an API to report resync progress.
This commit is contained in:
Poorna
2022-02-10 10:16:52 -08:00
committed by GitHub
parent a2230868e0
commit ed3418c046
12 changed files with 1717 additions and 139 deletions
+1 -3
View File
@@ -215,9 +215,7 @@ Existing object replication as detailed [here](https://aws.amazon.com/blogs/stor
Once existing object replication is enabled, all objects or object prefixes that satisfy the replication rules and were created prior to adding replication configuration OR while replication rules were disabled will be synced to the target cluster. Depending on the number of previously existing objects, the existing objects that are now eligible to be replicated will eventually be synced to the target cluster as the scanner schedules them. This may be slower depending on the load on the cluster, latency and size of the namespace.
In the rare event that target DR site is entirely lost and previously replicated objects to the DR cluster need to be re-replicated, `mc replicate resync alias/bucket` can be used to initiate a reset. This would initiate a re-sync between the two clusters on a lower priority as the scanner picks up these objects to re-sync.
This is an expensive operation and should be initiated only once - progress of the syncing can be monitored by looking at Prometheus metrics. If object version has been re-replicated, `mc stat --vid --debug` on this version shows an additional header `X-Minio-Replication-Reset-Status` with the replication timestamp and ResetID generated at the time of issuing the `mc replicate resync` command.
In the rare event that target DR site is entirely lost and previously replicated objects to the DR cluster need to be re-replicated, `mc replicate resync start alias/bucket --remote-bucket <arn>` can be used to initiate a reset. This would initiate a re-sync between the two clusters by walking the bucket namespace and replicating eligible objects that satisfy the existing objects replication rule specified in the replication config. The status of the resync operation can be viewed with `mc replicate resync status alias/bucket --remote-bucket <arn>`.
Note that ExistingObjectReplication needs to be enabled in the config via `mc replicate [add|edit]` by passing `existing-objects` as one of the values to `--replicate` flag. Only those objects meeting replication rules and having existing object replication enabled will be re-synced.