Split ReadRing.GetAll() into two functions

pkg/compactor/compactor_test.go

@@ -704,7 +704,7 @@ func TestCompactor_ShouldCompactOnlyUsersOwnedByTheInstanceOnShardingEnabledAndM
 	for _, c := range compactors {
 		cortex_testutil.Poll(t, 10*time.Second, len(compactors), func() interface{} {
 			// it is safe to access c.ring here, since we know that all compactors are Running now
-			rs, err := c.ring.GetAll(ring.Compactor)
+			rs, err := c.ring.GetAllHealthy(ring.Compactor)
 			if err != nil {
 				return 0
 			}

pkg/distributor/distributor.go

@@ -835,7 +835,7 @@ func (d *Distributor) AllUserStats(ctx context.Context) ([]UserIDStats, error) {
 	req := &client.UserStatsRequest{}
 	ctx = user.InjectOrgID(ctx, "1") // fake: ingester insists on having an org ID
 	// Not using d.ForReplicationSet(), so we can fail after first error.
-	replicationSet, err := d.ingestersRing.GetAll(ring.Read)
+	replicationSet, err := d.ingestersRing.GetAllHealthy(ring.Read)
 	if err != nil {
 		return nil, err
 	}

pkg/distributor/query.go

@@ -88,7 +88,7 @@ func (d *Distributor) GetIngestersForQuery(ctx context.Context, matchers ...*lab
 		lookbackPeriod := d.cfg.ShuffleShardingLookbackPeriod
 
 		if shardSize > 0 && lookbackPeriod > 0 {
-			return d.ingestersRing.ShuffleShardWithLookback(userID, shardSize, lookbackPeriod, time.Now()).GetAll(ring.Read)
+			return d.ingestersRing.ShuffleShardWithLookback(userID, shardSize, lookbackPeriod, time.Now()).GetReplicationSetForOperation(ring.Read)
 		}
 	}
 
@@ -101,7 +101,7 @@ func (d *Distributor) GetIngestersForQuery(ctx context.Context, matchers ...*lab
 		}
 	}
 
-	return d.ingestersRing.GetAll(ring.Read)
+	return d.ingestersRing.GetReplicationSetForOperation(ring.Read)
 }
 
 // GetIngestersForMetadata returns a replication set including all ingesters that should be queried
@@ -119,11 +119,11 @@ func (d *Distributor) GetIngestersForMetadata(ctx context.Context) (ring.Replica
 		lookbackPeriod := d.cfg.ShuffleShardingLookbackPeriod
 
 		if shardSize > 0 && lookbackPeriod > 0 {
-			return d.ingestersRing.ShuffleShardWithLookback(userID, shardSize, lookbackPeriod, time.Now()).GetAll(ring.Read)
+			return d.ingestersRing.ShuffleShardWithLookback(userID, shardSize, lookbackPeriod, time.Now()).GetReplicationSetForOperation(ring.Read)
 		}
 	}
 
-	return d.ingestersRing.GetAll(ring.Read)
+	return d.ingestersRing.GetReplicationSetForOperation(ring.Read)
 }
 
 // queryIngesters queries the ingesters via the older, sample-based API.

pkg/querier/blocks_store_replicated_set_test.go

@@ -342,7 +342,7 @@ func TestBlocksStoreReplicationSet_GetClientsFor(t *testing.T) {
 
 			// Wait until the ring client has initialised the state.
 			test.Poll(t, time.Second, true, func() interface{} {
-				all, err := r.GetAll(ring.Read)
+				all, err := r.GetAllHealthy(ring.Read)
 				return err == nil && len(all.Ingesters) > 0
 			})
 

pkg/ring/client/ring_service_discovery.go

@@ -6,7 +6,7 @@ import (
 
 func NewRingServiceDiscovery(r ring.ReadRing) PoolServiceDiscovery {
 	return func() ([]string, error) {
-		replicationSet, err := r.GetAll(ring.Read)
+		replicationSet, err := r.GetAllHealthy(ring.Reporting)
 		if err != nil {
 			return nil, err
 		}

pkg/ring/client/ring_service_discovery_test.go

@@ -58,6 +58,6 @@ type mockReadRing struct {
 	mockedErr            error
 }
 
-func (m *mockReadRing) GetAll(_ ring.Operation) (ring.ReplicationSet, error) {
+func (m *mockReadRing) GetAllHealthy(_ ring.Operation) (ring.ReplicationSet, error) {
 	return m.mockedReplicationSet, m.mockedErr
 }

pkg/ring/ring.go

@@ -44,7 +44,18 @@ type ReadRing interface {
 	// buf is a slice to be overwritten for the return value
 	// to avoid memory allocation; can be nil.
 	Get(key uint32, op Operation, buf []IngesterDesc) (ReplicationSet, error)
-	GetAll(op Operation) (ReplicationSet, error)
+
+	// GetAllHealthy returns all healthy instances in the ring, for the given operation.
+	// This function doesn't check if the quorum is honored, so doesn't fail if the number
+	// of unhealthy ingesters is greater than the tolerated max unavailable.
+	GetAllHealthy(op Operation) (ReplicationSet, error)
+
+	// GetReplicationSetForOperation returns all instances where the input operation should be executed.
+	// The resulting ReplicationSet doesn't necessarily contains all healthy instances
+	// in the ring, but could contain the minimum set of instances required to execute
+	// the input operation.
+	GetReplicationSetForOperation(op Operation) (ReplicationSet, error)
+
 	ReplicationFactor() int
 	IngesterCount() int
 
@@ -89,6 +100,10 @@ var (
 	// ErrInstanceNotFound is the error returned when trying to get information for an instance
 	// not registered within the ring.
 	ErrInstanceNotFound = errors.New("instance not found in the ring")
+
+	// ErrTooManyFailedIngesters is the error returned when there are too many failed ingesters for a
+	// specific operation.
+	ErrTooManyFailedIngesters = errors.New("too many failed ingesters")
 )
 
 // Config for a Ring
@@ -317,8 +332,30 @@ func (r *Ring) Get(key uint32, op Operation, buf []IngesterDesc) (ReplicationSet
 	}, nil
 }
 
-// GetAll returns all available ingesters in the ring.
-func (r *Ring) GetAll(op Operation) (ReplicationSet, error) {
+// GetAllHealthy implements ReadRing.
+func (r *Ring) GetAllHealthy(op Operation) (ReplicationSet, error) {
+	r.mtx.RLock()
+	defer r.mtx.RUnlock()
+
+	if r.ringDesc == nil || len(r.ringDesc.Ingesters) == 0 {
+		return ReplicationSet{}, ErrEmptyRing
+	}
+
+	ingesters := make([]IngesterDesc, 0, len(r.ringDesc.Ingesters))
+	for _, ingester := range r.ringDesc.Ingesters {
+		if r.IsHealthy(&ingester, op) {
+			ingesters = append(ingesters, ingester)
+		}
+	}
+
+	return ReplicationSet{
+		Ingesters: ingesters,
+		MaxErrors: 0,
+	}, nil
+}
+
+// GetReplicationSetForOperation implements ReadRing.
+func (r *Ring) GetReplicationSetForOperation(op Operation) (ReplicationSet, error) {
 	r.mtx.RLock()
 	defer r.mtx.RUnlock()
 
@@ -343,7 +380,7 @@ func (r *Ring) GetAll(op Operation) (ReplicationSet, error) {
 	}
 
 	if len(ingesters) < numRequired {
-		return ReplicationSet{}, fmt.Errorf("too many failed ingesters")
+		return ReplicationSet{}, ErrTooManyFailedIngesters
 	}
 
 	return ReplicationSet{