Ceph » rgw

The 'radosgw-admin sync status' command shows a timestamp for the "oldest incremental change not applied", but that only tells you about the one shard that's furthest behind.

A more detailed command should list the timestamps and sync delta for each shard. Commands already exist for 'radosgw-admin data sync status' and 'metadata sync status' that only print the local array of sync status markers. When implementing 'bucket sync status', I renamed the existing 'bucket sync status' command to 'bucket sync markers' - so I propose the same approach for data and metadata. That is, have 'data sync markers' print the markers only, and 'data sync status' print the per-shard comparison of timestamps between zones.

The output would be a json array of shards (possibly sorted by 'behind'):

[
    {
        "shard_id" : 0,
        "status" : "incremental-sync",
        "applied" : "2019-12-17 12:00:00",
        "latest" : "2019-12-17 12:00:10",
        "behind" : "10" 
    },
    ...
]