Method GetIngestersForMetadata

pkg/distributor/query.go:116–134

GetIngestersForMetadata returns a replication set including all ingesters that should be queried to fetch metadata (eg. label names/values or series).

(ctx context.Context)

// GetIngestersForMetadata returns a replication set including all ingesters that should be queried
// to fetch metadata (eg. label names/values or series).
func (d *Distributor) GetIngestersForMetadata(ctx context.Context) (ring.ReplicationSet, error) {
	userID, err := users.TenantID(ctx)
	if err != nil {
		return ring.ReplicationSet{}, err
	}

	// If shuffle sharding is enabled we should only query ingesters which are
	// part of the tenant's subring.
	if d.cfg.ShardingStrategy == util.ShardingStrategyShuffle {
		shardSize := d.limits.IngestionTenantShardSize(userID)
		lookbackPeriod := d.cfg.ShuffleShardingLookbackPeriod

		if shardSize > 0 && lookbackPeriod > 0 {
			return d.ingestersRing.ShuffleShardWithLookback(userID, shardSize, lookbackPeriod, time.Now()).GetReplicationSetForOperation(ring.Read)
		}
	}

	return d.ingestersRing.GetReplicationSetForOperation(ring.Read)
}

// mergeExemplarSets merges and dedupes two sets of already sorted exemplar pairs.
// Both a and b should be lists of exemplars from the same series.