rip out interning, except if we have multiple remote writes

Signed-off-by: Callum Styan <callumstyan@gmail.com>

go.mod

@@ -1,6 +1,6 @@
 module github.com/prometheus/prometheus
 
-go 1.21.0
+go 1.23.0
 
 toolchain go1.22.5
 

storage/remote/intern-refs

@@ -0,0 +1,46 @@
+goos: linux
+goarch: amd64
+pkg: github.com/prometheus/prometheus/storage/remote
+cpu: AMD Ryzen 9 5950X 16-Core Processor            
+BenchmarkStoreSeries/plain-32           	    4168	    256049 ns/op	  228660 B/op	    1596 allocs/op
+BenchmarkStoreSeries/plain-32           	    4500	    254302 ns/op	  228643 B/op	    1596 allocs/op
+BenchmarkStoreSeries/plain-32           	    4552	    255622 ns/op	  228618 B/op	    1596 allocs/op
+BenchmarkStoreSeries/plain-32           	    4460	    254980 ns/op	  228615 B/op	    1596 allocs/op
+BenchmarkStoreSeries/plain-32           	    4506	    259763 ns/op	  228626 B/op	    1596 allocs/op
+BenchmarkStoreSeries/externalLabels-32  	    1262	    895862 ns/op	  869235 B/op	    2596 allocs/op
+BenchmarkStoreSeries/externalLabels-32  	    1324	    897306 ns/op	  869256 B/op	    2597 allocs/op
+BenchmarkStoreSeries/externalLabels-32  	    1297	    894041 ns/op	  869225 B/op	    2597 allocs/op
+BenchmarkStoreSeries/externalLabels-32  	    1315	    907147 ns/op	  869157 B/op	    2596 allocs/op
+BenchmarkStoreSeries/externalLabels-32  	    1207	    895866 ns/op	  869218 B/op	    2597 allocs/op
+BenchmarkStoreSeries/relabel-32         	    1635	    784739 ns/op	  741725 B/op	    5597 allocs/op
+BenchmarkStoreSeries/relabel-32         	    1532	    727039 ns/op	  741748 B/op	    5598 allocs/op
+BenchmarkStoreSeries/relabel-32         	    1604	    729110 ns/op	  741750 B/op	    5597 allocs/op
+BenchmarkStoreSeries/relabel-32         	    1614	    729609 ns/op	  741696 B/op	    5597 allocs/op
+BenchmarkStoreSeries/relabel-32         	    1626	    727394 ns/op	  741669 B/op	    5597 allocs/op
+BenchmarkStoreSeries/externalLabels+relabel-32         	     987	   1208797 ns/op	  837849 B/op	    5597 allocs/op
+BenchmarkStoreSeries/externalLabels+relabel-32         	     985	   1197194 ns/op	  837867 B/op	    5597 allocs/op
+BenchmarkStoreSeries/externalLabels+relabel-32         	     992	   1195505 ns/op	  837853 B/op	    5597 allocs/op
+BenchmarkStoreSeries/externalLabels+relabel-32         	     999	   1201181 ns/op	  837831 B/op	    5597 allocs/op
+BenchmarkStoreSeries/externalLabels+relabel-32         	    1000	   1195945 ns/op	  837889 B/op	    5597 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/plain-32             	    2469	    475513 ns/op	  436320 B/op	    2731 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/plain-32             	    2523	    478113 ns/op	  436257 B/op	    2731 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/plain-32             	    2458	    475820 ns/op	  436279 B/op	    2731 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/plain-32             	    2492	    472694 ns/op	  436243 B/op	    2731 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/plain-32             	    2437	    476160 ns/op	  436259 B/op	    2731 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/externalLabels-32    	     679	   1747548 ns/op	 1717397 B/op	    4731 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/externalLabels-32    	     676	   1754213 ns/op	 1717468 B/op	    4732 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/externalLabels-32    	     674	   1739374 ns/op	 1717653 B/op	    4732 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/externalLabels-32    	     679	   1738507 ns/op	 1717426 B/op	    4732 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/externalLabels-32    	     694	   1739284 ns/op	 1717384 B/op	    4732 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/relabel-32           	     850	   1399855 ns/op	 1462383 B/op	   10733 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/relabel-32           	     834	   1405426 ns/op	 1462345 B/op	   10733 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/relabel-32           	     842	   1424322 ns/op	 1462449 B/op	   10734 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/relabel-32           	     841	   1404540 ns/op	 1462356 B/op	   10733 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/relabel-32           	     843	   1414279 ns/op	 1462380 B/op	   10733 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/externalLabels+relabel-32         	     508	   2351248 ns/op	 1654492 B/op	   10733 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/externalLabels+relabel-32         	     507	   2368400 ns/op	 1654660 B/op	   10734 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/externalLabels+relabel-32         	     505	   2347374 ns/op	 1654649 B/op	   10734 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/externalLabels+relabel-32         	     507	   2349636 ns/op	 1654516 B/op	   10733 allocs/op
+BenchmarkStoreSeries_TwoEndpoints/externalLabels+relabel-32         	     504	   2349570 ns/op	 1654583 B/op	   10733 allocs/op
+PASS
+ok  	github.com/prometheus/prometheus/storage/remote	53.470s

storage/remote/intern.go

@@ -23,6 +23,8 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prometheus/prometheus/model/labels"
+	"github.com/prometheus/prometheus/tsdb/chunks"
 	"go.uber.org/atomic"
 )
 
@@ -35,52 +37,32 @@ var noReferenceReleases = promauto.NewCounter(prometheus.CounterOpts{
 
 type pool struct {
 	mtx          sync.RWMutex
-	pool map[string]*entry
+	pool         map[chunks.HeadSeriesRef]*entry
+	shouldIntern bool
 }
 
 type entry struct {
 	refs atomic.Int64
-
+	lset labels.Labels
-	s string
 }
 
-func newEntry(s string) *entry {
+func newEntry(lset labels.Labels) *entry {
-	return &entry{s: s}
+	return &entry{lset: lset}
 }
 
-func newPool() *pool {
+func newPool(shouldIntern bool) *pool {
 	return &pool{
-		pool: map[string]*entry{},
+		pool:         map[chunks.HeadSeriesRef]*entry{},
+		shouldIntern: shouldIntern,
 	}
 }
 
-func (p *pool) intern(s string) string {
+func (p *pool) release(ref chunks.HeadSeriesRef) {
-	if s == "" {
+	if !p.shouldIntern {
-		return ""
+		return
 	}
-
 	p.mtx.RLock()
-	interned, ok := p.pool[s]
+	interned, ok := p.pool[ref]
-	p.mtx.RUnlock()
-	if ok {
-		interned.refs.Inc()
-		return interned.s
-	}
-	p.mtx.Lock()
-	defer p.mtx.Unlock()
-	if interned, ok := p.pool[s]; ok {
-		interned.refs.Inc()
-		return interned.s
-	}
-
-	p.pool[s] = newEntry(s)
-	p.pool[s].refs.Store(1)
-	return s
-}
-
-func (p *pool) release(s string) {
-	p.mtx.RLock()
-	interned, ok := p.pool[s]
 	p.mtx.RUnlock()
 
 	if !ok {
@@ -98,5 +80,33 @@ func (p *pool) release(s string) {
 	if interned.refs.Load() != 0 {
 		return
 	}
-	delete(p.pool, s)
+	delete(p.pool, ref)
+}
+
+func (p *pool) intern(ref chunks.HeadSeriesRef, lset labels.Labels) labels.Labels {
+	if !p.shouldIntern {
+		return lset
+	}
+
+	p.mtx.RLock()
+	interned, ok := p.pool[ref]
+	p.mtx.RUnlock()
+	if ok {
+		interned.refs.Inc()
+		return interned.lset
+	}
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+	if interned, ok := p.pool[ref]; ok {
+		interned.refs.Inc()
+		return interned.lset
+	}
+
+	if len(lset) == 0 {
+		return nil
+	}
+
+	p.pool[ref] = newEntry(lset)
+	p.pool[ref].refs.Store(1)
+	return p.pool[ref].lset
 }

storage/remote/intern_test.go

@@ -24,67 +24,79 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/require"
+
+	"github.com/prometheus/prometheus/model/labels"
+	"github.com/prometheus/prometheus/tsdb/chunks"
 )
 
 func TestIntern(t *testing.T) {
-	interner := newPool()
+	interner := newPool(true)
-	testString := "TestIntern"
+	testString := "TestIntern_DeleteRef"
-	interner.intern(testString)
+	ref := chunks.HeadSeriesRef(1234)
-	interned, ok := interner.pool[testString]
+
+	lset := labels.FromStrings("name", testString)
+	interner.intern(ref, lset)
+	interned, ok := interner.pool[ref]
 
 	require.True(t, ok)
+	require.Equal(t, lset, interned.lset)
 	require.Equal(t, int64(1), interned.refs.Load(), fmt.Sprintf("expected refs to be 1 but it was %d", interned.refs.Load()))
 }
 
 func TestIntern_MultiRef(t *testing.T) {
-	interner := newPool()
+	interner := newPool(true)
-	testString := "TestIntern_MultiRef"
+	testString := "TestIntern_DeleteRef"
+	ref := chunks.HeadSeriesRef(1234)
 
-	interner.intern(testString)
+	lset := labels.FromStrings("name", testString)
-	interned, ok := interner.pool[testString]
+	interner.intern(ref, lset)
+	interned, ok := interner.pool[ref]
 
 	require.True(t, ok)
+	require.Equal(t, lset, interned.lset)
 	require.Equal(t, int64(1), interned.refs.Load(), fmt.Sprintf("expected refs to be 1 but it was %d", interned.refs.Load()))
 
-	interner.intern(testString)
+	interner.intern(ref, lset)
-	interned, ok = interner.pool[testString]
+	interned, ok = interner.pool[ref]
 
-	require.True(t, ok)
+	require.NotNil(t, interned)
 	require.Equal(t, int64(2), interned.refs.Load(), fmt.Sprintf("expected refs to be 2 but it was %d", interned.refs.Load()))
 }
 
 func TestIntern_DeleteRef(t *testing.T) {
-	interner := newPool()
+	interner := newPool(true)
 	testString := "TestIntern_DeleteRef"
+	ref := chunks.HeadSeriesRef(1234)
+	interner.intern(ref, labels.FromStrings("name", testString))
+	interned, ok := interner.pool[ref]
 
-	interner.intern(testString)
+	require.NotNil(t, interned)
-	interned, ok := interner.pool[testString]
-
-	require.True(t, ok)
 	require.Equal(t, int64(1), interned.refs.Load(), fmt.Sprintf("expected refs to be 1 but it was %d", interned.refs.Load()))
 
-	interner.release(testString)
+	interner.release(ref)
-	_, ok = interner.pool[testString]
+	_, ok = interner.pool[ref]
 	require.False(t, ok)
 }
 
 func TestIntern_MultiRef_Concurrent(t *testing.T) {
-	interner := newPool()
+	interner := newPool(true)
 	testString := "TestIntern_MultiRef_Concurrent"
+	ref := chunks.HeadSeriesRef(1234)
 
-	interner.intern(testString)
+	interner.intern(ref, labels.FromStrings("name", testString))
-	interned, ok := interner.pool[testString]
+	interned, ok := interner.pool[ref]
-	require.True(t, ok)
+
+	require.NotNil(t, interned)
 	require.Equal(t, int64(1), interned.refs.Load(), fmt.Sprintf("expected refs to be 1 but it was %d", interned.refs.Load()))
 
-	go interner.release(testString)
+	go interner.release(ref)
 
-	interner.intern(testString)
+	interner.intern(ref, labels.FromStrings("name", testString))
 
 	time.Sleep(time.Millisecond)
 
 	interner.mtx.RLock()
-	interned, ok = interner.pool[testString]
+	interned, ok = interner.pool[ref]
 	interner.mtx.RUnlock()
 	require.True(t, ok)
 	require.Equal(t, int64(1), interned.refs.Load(), fmt.Sprintf("expected refs to be 1 but it was %d", interned.refs.Load()))

storage/remote/queue_manager.go

@@ -702,8 +702,13 @@ outer:
 			continue
 		}
 		t.seriesMtx.Lock()
-		lbls, ok := t.seriesLabels[s.Ref]
+		var lbls labels.Labels
-		if !ok {
+		if t.interner.shouldIntern {
+			lbls = t.interner.intern(s.Ref, nil)
+		} else {
+			lbls = t.seriesLabels[s.Ref]
+		}
+		if len(lbls) == 0 {
 			t.dataDropped.incr(1)
 			if _, ok := t.droppedSeries[s.Ref]; !ok {
 				level.Info(t.logger).Log("msg", "Dropped sample for series that was not explicitly dropped via relabelling", "ref", s.Ref)
@@ -764,8 +769,13 @@ outer:
 			continue
 		}
 		t.seriesMtx.Lock()
-		lbls, ok := t.seriesLabels[e.Ref]
+		var lbls labels.Labels
-		if !ok {
+		if t.interner.shouldIntern {
+			lbls = t.interner.intern(e.Ref, nil)
+		} else {
+			lbls = t.seriesLabels[e.Ref]
+		}
+		if len(lbls) == 0 {
 			// Track dropped exemplars in the same EWMA for sharding calc.
 			t.dataDropped.incr(1)
 			if _, ok := t.droppedSeries[e.Ref]; !ok {
@@ -821,8 +831,13 @@ outer:
 			continue
 		}
 		t.seriesMtx.Lock()
-		lbls, ok := t.seriesLabels[h.Ref]
+		var lbls labels.Labels
-		if !ok {
+		if t.interner.shouldIntern {
+			lbls = t.interner.intern(h.Ref, nil)
+		} else {
+			lbls = t.seriesLabels[h.Ref]
+		}
+		if len(lbls) == 0 {
 			t.dataDropped.incr(1)
 			if _, ok := t.droppedSeries[h.Ref]; !ok {
 				level.Info(t.logger).Log("msg", "Dropped histogram for series that was not explicitly dropped via relabelling", "ref", h.Ref)
@@ -876,8 +891,13 @@ outer:
 			continue
 		}
 		t.seriesMtx.Lock()
-		lbls, ok := t.seriesLabels[h.Ref]
+		var lbls labels.Labels
-		if !ok {
+		if t.interner.shouldIntern {
+			lbls = t.interner.intern(h.Ref, nil)
+		} else {
+			lbls = t.seriesLabels[h.Ref]
+		}
+		if len(lbls) == 0 {
 			t.dataDropped.incr(1)
 			if _, ok := t.droppedSeries[h.Ref]; !ok {
 				level.Info(t.logger).Log("msg", "Dropped histogram for series that was not explicitly dropped via relabelling", "ref", h.Ref)
@@ -960,9 +980,6 @@ func (t *QueueManager) Stop() {
 
 	// On shutdown, release the strings in the labels from the intern pool.
 	t.seriesMtx.Lock()
-	for _, labels := range t.seriesLabels {
-		t.releaseLabels(labels)
-	}
 	t.seriesMtx.Unlock()
 	t.metrics.unregister()
 }
@@ -985,16 +1002,12 @@ func (t *QueueManager) StoreSeries(series []record.RefSeries, index int) {
 			continue
 		}
 		lbls := t.builder.Labels()
-		t.internLabels(lbls)
+		if t.interner.shouldIntern {
-
+			t.interner.intern(s.Ref, lbls)
-		// We should not ever be replacing a series labels in the map, but just
+		} else {
-		// in case we do we need to ensure we do not leak the replaced interned
-		// strings.
-		if orig, ok := t.seriesLabels[s.Ref]; ok {
-			t.releaseLabels(orig)
-		}
 			t.seriesLabels[s.Ref] = lbls
 		}
+	}
 }
 
 // StoreMetadata keeps track of known series' metadata for lookups when sending samples to remote.
@@ -1037,8 +1050,9 @@ func (t *QueueManager) SeriesReset(index int) {
 	for k, v := range t.seriesSegmentIndexes {
 		if v < index {
 			delete(t.seriesSegmentIndexes, k)
-			t.releaseLabels(t.seriesLabels[k])
+			t.interner.release(k)
-			delete(t.seriesLabels, k)
+			//t.releaseLabels(t.seriesLabels[k])
+			//delete(t.seriesLabels, k)
 			delete(t.seriesMetadata, k)
 			delete(t.droppedSeries, k)
 		}
@@ -1059,14 +1073,6 @@ func (t *QueueManager) client() WriteClient {
 	return t.storeClient
 }
 
-func (t *QueueManager) internLabels(lbls labels.Labels) {
-	lbls.InternStrings(t.interner.intern)
-}
-
-func (t *QueueManager) releaseLabels(ls labels.Labels) {
-	ls.ReleaseStrings(t.interner.release)
-}
-
 // processExternalLabels merges externalLabels into b. If b contains
 // a label in externalLabels, the value in b wins.
 func processExternalLabels(b *labels.Builder, externalLabels []labels.Label) {

storage/remote/queue_manager_test.go

@@ -294,7 +294,6 @@ func TestSampleDelivery(t *testing.T) {
 			qm.AppendHistograms(histograms[:len(histograms)/2])
 			qm.AppendFloatHistograms(floatHistograms[:len(floatHistograms)/2])
 			c.waitForExpectedData(t, 30*time.Second)
-
 			// Send second half of data.
 			c.expectSamples(samples[len(samples)/2:], series)
 			c.expectExemplars(exemplars[len(exemplars)/2:], series)
@@ -319,7 +318,7 @@ func newTestClientAndQueueManager(t testing.TB, flushDeadline time.Duration, pro
 func newTestQueueManager(t testing.TB, cfg config.QueueConfig, mcfg config.MetadataConfig, deadline time.Duration, c WriteClient, protoMsg config.RemoteWriteProtoMsg) *QueueManager {
 	dir := t.TempDir()
 	metrics := newQueueManagerMetrics(nil, "", "")
-	m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, mcfg, labels.EmptyLabels(), nil, c, deadline, newPool(), newHighestTimestampMetric(), nil, false, false, protoMsg)
+	m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, mcfg, labels.EmptyLabels(), nil, c, deadline, newPool(false), newHighestTimestampMetric(), nil, false, false, protoMsg)
 
 	return m
 }
@@ -772,7 +771,7 @@ func TestDisableReshardOnRetry(t *testing.T) {
 		}
 	)
 
-	m := NewQueueManager(metrics, nil, nil, nil, "", newEWMARate(ewmaWeight, shardUpdateDuration), cfg, mcfg, labels.EmptyLabels(), nil, client, 0, newPool(), newHighestTimestampMetric(), nil, false, false, config.RemoteWriteProtoMsgV1)
+	m := NewQueueManager(metrics, nil, nil, nil, "", newEWMARate(ewmaWeight, shardUpdateDuration), cfg, mcfg, labels.EmptyLabels(), nil, client, 0, newPool(false), newHighestTimestampMetric(), nil, false, false, config.RemoteWriteProtoMsgV1)
 	m.StoreSeries(fakeSeries, 0)
 
 	// Attempt to samples while the manager is running. We immediately stop the
@@ -1385,7 +1384,7 @@ func BenchmarkStoreSeries(b *testing.B) {
 				cfg := config.DefaultQueueConfig
 				mcfg := config.DefaultMetadataConfig
 				metrics := newQueueManagerMetrics(nil, "", "")
-				m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, mcfg, labels.EmptyLabels(), nil, c, defaultFlushDeadline, newPool(), newHighestTimestampMetric(), nil, false, false, config.RemoteWriteProtoMsgV1)
+				m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, mcfg, labels.EmptyLabels(), nil, c, defaultFlushDeadline, newPool(false), newHighestTimestampMetric(), nil, false, false, config.RemoteWriteProtoMsgV1)
 				m.externalLabels = tc.externalLabels
 				m.relabelConfigs = tc.relabelConfigs
 
@@ -1437,13 +1436,13 @@ func BenchmarkStoreSeries_TwoEndpoints(b *testing.B) {
 				cfg := config.DefaultQueueConfig
 				mcfg := config.DefaultMetadataConfig
 				metrics := newQueueManagerMetrics(nil, "", "")
-				m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, mcfg, labels.EmptyLabels(), nil, c, defaultFlushDeadline, newPool(), newHighestTimestampMetric(), nil, false, false, config.RemoteWriteProtoMsgV1)
+				m := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, mcfg, labels.EmptyLabels(), nil, c, defaultFlushDeadline, newPool(false), newHighestTimestampMetric(), nil, false, false, config.RemoteWriteProtoMsgV1)
 				m.externalLabels = tc.externalLabels
 				m.relabelConfigs = tc.relabelConfigs
 
 				m.StoreSeries(series, 0)
 
-				m2 := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, mcfg, labels.EmptyLabels(), nil, c, defaultFlushDeadline, newPool(), newHighestTimestampMetric(), nil, false, false, config.RemoteWriteProtoMsgV1)
+				m2 := NewQueueManager(metrics, nil, nil, nil, dir, newEWMARate(ewmaWeight, shardUpdateDuration), cfg, mcfg, labels.EmptyLabels(), nil, c, defaultFlushDeadline, newPool(false), newHighestTimestampMetric(), nil, false, false, config.RemoteWriteProtoMsgV1)
 				m2.externalLabels = tc.externalLabels
 				m2.relabelConfigs = tc.relabelConfigs
 
@@ -1483,7 +1482,7 @@ func BenchmarkStartup(b *testing.B) {
 		// todo: test with new proto type(s)
 		m := NewQueueManager(metrics, nil, nil, logger, dir,
 			newEWMARate(ewmaWeight, shardUpdateDuration),
-			cfg, mcfg, labels.EmptyLabels(), nil, c, 1*time.Minute, newPool(), newHighestTimestampMetric(), nil, false, false, config.RemoteWriteProtoMsgV1)
+			cfg, mcfg, labels.EmptyLabels(), nil, c, 1*time.Minute, newPool(false), newHighestTimestampMetric(), nil, false, false, config.RemoteWriteProtoMsgV1)
 		m.watcher.SetStartTime(timestamp.Time(math.MaxInt64))
 		m.watcher.MaxSegment = segments[len(segments)-2]
 		err := m.watcher.Run()

storage/remote/write.go

@@ -91,7 +91,7 @@ func NewWriteStorage(logger log.Logger, reg prometheus.Registerer, dir string, f
 		flushDeadline:     flushDeadline,
 		samplesIn:         newEWMARate(ewmaWeight, shardUpdateDuration),
 		dir:               dir,
-		interner:          newPool(),
+		interner:          newPool(false),
 		scraper:           sm,
 		quit:              make(chan struct{}),
 		metadataInWAL:     metadataInWal,
@@ -227,6 +227,10 @@ func (rws *WriteStorage) ApplyConfig(conf *config.Config) error {
 		q.Stop()
 	}
 
+	if len(newHashes) > 1 {
+		rws.interner.shouldIntern = true
+	}
+
 	for _, hash := range newHashes {
 		newQueues[hash].Start()
 	}