Replication of object version and metadata

If an object meets replication rules as set in the replication configuration, `X-Amz-Replication-Status` is first set to `PENDING` as the PUT operation completes and replication is queued (unless synchronous replication is in place). After replication is performed, the metadata on the source object version changes to `COMPLETED` or `FAILED` depending on whether replication succeeded. The object version on the target shows `X-Amz-Replication-Status`...

		if t.Replicate {
			return true
		}
	}
	return false
}

// Synchronous returns true if at least one target qualifies for synchronous replication
func (d ReplicateDecision) Synchronous() bool {
	for _, t := range d.targetsMap {
		if t.Synchronous {
			return true
		}
	}
	return false
}

func (d ReplicateDecision) String() string {
	b := new(bytes.Buffer)

### Sync/Async Replication

By default, replication is completed asynchronously. If synchronous replication is desired, set the --sync flag while adding a
remote replication target using the `mc admin bucket remote add` command. For mc releases on or after `RELEASE.2022-12-24T15-21-38Z`, the 

			Optional:    true,
			Type:        "boolean",
		},
		config.HelpKV{
			Key:         apiSyncEvents,
			Description: "set to enable synchronous bucket notifications" + defaultHelpPostfix(apiSyncEvents),
			Optional:    true,
			Type:        "boolean",
		},
		config.HelpKV{
			Key:         apiObjectMaxVersions,

		// whether to replicate as the target could be temporarily down
		opts.TargetArn = tgtArn
		replicate := cfg.Replicate(opts)
		var synchronous bool
		if tgt != nil {
			synchronous = tgt.replicateSync
		}
		dsc.Set(newReplicateTargetDecision(tgtArn, replicate, synchronous))
	}
	return dsc
}

// Standard headers that needs to be extracted from User metadata.
var standardHeaders = []string{

```
cat ${HADOOP_CONF_DIR}/core-site.xml | kv-pairify | grep "mapred"

mapred.maxthreads.generate.mapoutput=2 # Num threads to write map outputs
mapred.maxthreads.partition.closer=0 # Asynchronous map flushers
mapreduce.fileoutputcommitter.algorithm.version=2 # Use the latest committer version
mapreduce.job.reduce.slowstart.completedmaps=0.99 # 99% map, then reduce

root_access                     (boolean)   turn 'off' root credential access for all API calls including s3, admin operations (default: 'on')
sync_events                     (boolean)   set to enable synchronous bucket notifications (default: 'off')
```

or environment variables

```
MINIO_API_REQUESTS_MAX                    (number)    set the maximum number of concurrent requests (default: '0')

		}
	}

	for i, version := range x.versions {
		if version.header.VersionID != uv || version.header.Type != ObjectType {
			continue
		}
		// if uv has tiered content we add a
		// free-version to track it for asynchronous
		// deletion via scanner.
		ver, err := x.getIdx(i)
		if err != nil {
			return err
		}

		if freeVersion, toFree := ver.ObjectV2.InitFreeVersion(fi); toFree {
			return x.addVersion(freeVersion)

	targetIDSet := evnot.bucketRulesMap[args.BucketName].Match(args.EventName, args.Object.Name)
	evnot.RUnlock()

	if len(targetIDSet) == 0 {
		return
	}

	// If MINIO_API_SYNC_EVENTS is set, send events synchronously.
	evnot.targetList.Send(args.ToEvent(true), targetIDSet, globalAPIConfig.isSyncEventsEnabled())
}

type eventArgs struct {
	EventName    event.Name
	BucketName   string
	Object       ObjectInfo

			Optional:    true,
			Type:        "on|off",
		},
		config.HelpKV{
			Key:         target.NATSStreamingAsync,
			Description: "[DEPRECATED] set to 'on', to enable asynchronous publish",
			Optional:    true,
			Type:        "on|off",
		},
		config.HelpKV{
			Key:         target.NATSStreamingMaxPubAcksInFlight,