Add new query inflight request on ingester

CHANGELOG.md

@@ -8,6 +8,7 @@
 * [FEATURE] Ingester: Experimental: Enable native histogram ingestion via `-blocks-storage.tsdb.enable-native-histograms` flag. #5986
 * [FEATURE] Query Frontend: Added a query rejection mechanism to block resource-intensive queries. #6005
 * [FEATURE] OTLP: Support ingesting OTLP exponential metrics as native histograms. #6071
+* [FEATURE] Ingester: Add `ingester.instance-limits.max-inflight-query-requests` to allow limiting ingester concurrent queries. #6081
 * [ENHANCEMENT] rulers: Add support to persist tokens in rulers. #5987
 * [ENHANCEMENT] Query Frontend/Querier: Added store gateway postings touched count and touched size in Querier stats and log in Query Frontend. #5892
 * [ENHANCEMENT] Query Frontend/Querier: Returns `warnings` on prometheus query responses. #5916

docs/configuration/config-file-reference.md

@@ -2961,6 +2961,11 @@ instance_limits:
   # CLI flag: -ingester.instance-limits.max-inflight-push-requests
   [max_inflight_push_requests: <int> | default = 0]
 
+  # Max inflight query requests that this ingester can handle (across all
+  # tenants). Additional requests will be rejected. 0 = unlimited.
+  # CLI flag: -ingester.instance-limits.max-inflight-query-requests
+  [max_inflight_query_requests: <int> | default = 0]
+
 # Comma-separated list of metric names, for which
 # -ingester.max-series-per-metric and -ingester.max-global-series-per-metric
 # limits will be ignored. Does not affect max-series-per-user or

pkg/ingester/ingester.go

@@ -155,6 +155,7 @@ func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
 	f.Int64Var(&cfg.DefaultLimits.MaxInMemoryTenants, "ingester.instance-limits.max-tenants", 0, "Max users that this ingester can hold. Requests from additional users will be rejected. This limit only works when using blocks engine. 0 = unlimited.")
 	f.Int64Var(&cfg.DefaultLimits.MaxInMemorySeries, "ingester.instance-limits.max-series", 0, "Max series that this ingester can hold (across all tenants). Requests to create additional series will be rejected. This limit only works when using blocks engine. 0 = unlimited.")
 	f.Int64Var(&cfg.DefaultLimits.MaxInflightPushRequests, "ingester.instance-limits.max-inflight-push-requests", 0, "Max inflight push requests that this ingester can handle (across all tenants). Additional requests will be rejected. 0 = unlimited.")
+	f.Int64Var(&cfg.DefaultLimits.MaxInflightQueryRequests, "ingester.instance-limits.max-inflight-query-requests", 0, "Max inflight query requests that this ingester can handle (across all tenants). Additional requests will be rejected. 0 = unlimited.")
 
 	f.StringVar(&cfg.IgnoreSeriesLimitForMetricNames, "ingester.ignore-series-limit-for-metric-names", "", "Comma-separated list of metric names, for which -ingester.max-series-per-metric and -ingester.max-global-series-per-metric limits will be ignored. Does not affect max-series-per-user or max-global-series-per-metric limits.")
 
@@ -1401,9 +1402,6 @@ func (i *Ingester) QueryExemplars(ctx context.Context, req *client.ExemplarQuery
 		return nil, err
 	}
 
-	c := i.trackInflightQueryRequest()
-	defer c()
-
 	userID, err := tenant.TenantID(ctx)
 	if err != nil {
 		return nil, err
@@ -1426,8 +1424,15 @@ func (i *Ingester) QueryExemplars(ctx context.Context, req *client.ExemplarQuery
 		return nil, err
 	}
 
+	// We will report *this* request in the error too.
+	c, err := i.trackInflightQueryRequest()
+	if err != nil {
+		return nil, err
+	}
+
 	// It's not required to sort series from a single ingester because series are sorted by the Exemplar Storage before returning from Select.
 	res, err := q.Select(from, through, matchers...)
+	c()
 	if err != nil {
 		return nil, err
 	}
@@ -1452,17 +1457,13 @@ func (i *Ingester) QueryExemplars(ctx context.Context, req *client.ExemplarQuery
 
 // LabelValues returns all label values that are associated with a given label name.
 func (i *Ingester) LabelValues(ctx context.Context, req *client.LabelValuesRequest) (*client.LabelValuesResponse, error) {
-	c := i.trackInflightQueryRequest()
-	defer c()
 	resp, cleanup, err := i.labelsValuesCommon(ctx, req)
 	defer cleanup()
 	return resp, err
 }
 
 // LabelValuesStream returns all label values that are associated with a given label name.
 func (i *Ingester) LabelValuesStream(req *client.LabelValuesRequest, stream client.Ingester_LabelValuesStreamServer) error {
-	c := i.trackInflightQueryRequest()
-	defer c()
 	resp, cleanup, err := i.labelsValuesCommon(stream.Context(), req)
 	defer cleanup()
 
@@ -1525,6 +1526,11 @@ func (i *Ingester) labelsValuesCommon(ctx context.Context, req *client.LabelValu
 		q.Close()
 	}
 
+	c, err := i.trackInflightQueryRequest()
+	if err != nil {
+		return nil, cleanup, err
+	}
+	defer c()
 	vals, _, err := q.LabelValues(ctx, labelName, matchers...)
 	if err != nil {
 		return nil, cleanup, err
@@ -1537,17 +1543,13 @@ func (i *Ingester) labelsValuesCommon(ctx context.Context, req *client.LabelValu
 
 // LabelNames return all the label names.
 func (i *Ingester) LabelNames(ctx context.Context, req *client.LabelNamesRequest) (*client.LabelNamesResponse, error) {
-	c := i.trackInflightQueryRequest()
-	defer c()
 	resp, cleanup, err := i.labelNamesCommon(ctx, req)
 	defer cleanup()
 	return resp, err
 }
 
 // LabelNamesStream return all the label names.
 func (i *Ingester) LabelNamesStream(req *client.LabelNamesRequest, stream client.Ingester_LabelNamesStreamServer) error {
-	c := i.trackInflightQueryRequest()
-	defer c()
 	resp, cleanup, err := i.labelNamesCommon(stream.Context(), req)
 	defer cleanup()
 
@@ -1605,6 +1607,11 @@ func (i *Ingester) labelNamesCommon(ctx context.Context, req *client.LabelNamesR
 		q.Close()
 	}
 
+	c, err := i.trackInflightQueryRequest()
+	if err != nil {
+		return nil, cleanup, err
+	}
+	defer c()
 	names, _, err := q.LabelNames(ctx)
 	if err != nil {
 		return nil, cleanup, err
@@ -1831,9 +1838,6 @@ func (i *Ingester) QueryStream(req *client.QueryRequest, stream client.Ingester_
 		return err
 	}
 
-	c := i.trackInflightQueryRequest()
-	defer c()
-
 	spanlog, ctx := spanlogger.New(stream.Context(), "QueryStream")
 	defer spanlog.Finish()
 
@@ -1879,11 +1883,18 @@ func (i *Ingester) QueryStream(req *client.QueryRequest, stream client.Ingester_
 	return nil
 }
 
-func (i *Ingester) trackInflightQueryRequest() func() {
+func (i *Ingester) trackInflightQueryRequest() (func(), error) {
+	gl := i.getInstanceLimits()
+	if gl != nil && gl.MaxInflightQueryRequests > 0 {
+		if i.inflightQueryRequests.Load() >= gl.MaxInflightQueryRequests {
+			return nil, errTooManyInflightQueryRequests
+		}
+	}
+
 	i.maxInflightQueryRequests.Track(i.inflightQueryRequests.Inc())
 	return func() {
 		i.inflightQueryRequests.Dec()
-	}
+	}, nil
 }
 
 // queryStreamChunks streams metrics from a TSDB. This implements the client.IngesterServer interface
@@ -1894,8 +1905,13 @@ func (i *Ingester) queryStreamChunks(ctx context.Context, db *userTSDB, from, th
 	}
 	defer q.Close()
 
+	c, err := i.trackInflightQueryRequest()
+	if err != nil {
+		return 0, 0, 0, err
+	}
 	// It's not required to return sorted series because series are sorted by the Cortex querier.
 	ss := q.Select(ctx, false, nil, matchers...)
+	c()
 	if ss.Err() != nil {
 		return 0, 0, 0, ss.Err()
 	}

pkg/ingester/ingester_test.go

@@ -2279,6 +2279,33 @@ func Test_Ingester_LabelValues(t *testing.T) {
 	}
 }
 
+func Test_Ingester_LabelValue_MaxInflighQueryRequest(t *testing.T) {
+	cfg := defaultIngesterTestConfig(t)
+	cfg.DefaultLimits.MaxInflightQueryRequests = 1
+	i, err := prepareIngesterWithBlocksStorage(t, cfg, prometheus.NewRegistry())
+	require.NoError(t, err)
+	require.NoError(t, services.StartAndAwaitRunning(context.Background(), i))
+	defer services.StopAndAwaitTerminated(context.Background(), i) //nolint:errcheck
+
+	// Wait until it's ACTIVE
+	test.Poll(t, 1*time.Second, ring.ACTIVE, func() interface{} {
+		return i.lifecycler.GetState()
+	})
+
+	i.inflightQueryRequests.Add(1)
+
+	// Mock request
+	ctx := user.InjectOrgID(context.Background(), "test")
+
+	wreq, _ := mockWriteRequest(t, labels.Labels{{Name: labels.MetricName, Value: "test_1"}, {Name: "status", Value: "200"}, {Name: "route", Value: "get_user"}}, 1, 100000)
+	_, err = i.Push(ctx, wreq)
+	require.NoError(t, err)
+
+	rreq := &client.LabelValuesRequest{}
+	_, err = i.LabelValues(ctx, rreq)
+	require.Error(t, err)
+}
+
 func Test_Ingester_Query(t *testing.T) {
 	series := []struct {
 		lbls      labels.Labels
@@ -2409,6 +2436,35 @@ func Test_Ingester_Query(t *testing.T) {
 		})
 	}
 }
+
+func Test_Ingester_Query_MaxInflighQueryRequest(t *testing.T) {
+	cfg := defaultIngesterTestConfig(t)
+	cfg.DefaultLimits.MaxInflightQueryRequests = 1
+	i, err := prepareIngesterWithBlocksStorage(t, cfg, prometheus.NewRegistry())
+	require.NoError(t, err)
+	require.NoError(t, services.StartAndAwaitRunning(context.Background(), i))
+	defer services.StopAndAwaitTerminated(context.Background(), i) //nolint:errcheck
+
+	// Wait until it's ACTIVE
+	test.Poll(t, 1*time.Second, ring.ACTIVE, func() interface{} {
+		return i.lifecycler.GetState()
+	})
+
+	i.inflightQueryRequests.Add(1)
+
+	// Mock request
+	ctx := user.InjectOrgID(context.Background(), "test")
+
+	wreq, _ := mockWriteRequest(t, labels.Labels{{Name: labels.MetricName, Value: "test_1"}, {Name: "status", Value: "200"}, {Name: "route", Value: "get_user"}}, 1, 100000)
+	_, err = i.Push(ctx, wreq)
+	require.NoError(t, err)
+
+	rreq := &client.QueryRequest{}
+	s := &mockQueryStreamServer{ctx: ctx}
+	err = i.QueryStream(rreq, s)
+	require.Error(t, err)
+}
+
 func TestIngester_Query_ShouldNotCreateTSDBIfDoesNotExists(t *testing.T) {
 	i, err := prepareIngesterWithBlocksStorage(t, defaultIngesterTestConfig(t), prometheus.NewRegistry())
 	require.NoError(t, err)
@@ -4949,6 +5005,33 @@ func TestIngester_MaxExemplarsFallBack(t *testing.T) {
 	require.Equal(t, maxExemplars, int64(5))
 }
 
+func Test_Ingester_QueryExemplar_MaxInflighQueryRequest(t *testing.T) {
+	cfg := defaultIngesterTestConfig(t)
+	cfg.DefaultLimits.MaxInflightQueryRequests = 1
+	i, err := prepareIngesterWithBlocksStorage(t, cfg, prometheus.NewRegistry())
+	require.NoError(t, err)
+	require.NoError(t, services.StartAndAwaitRunning(context.Background(), i))
+	defer services.StopAndAwaitTerminated(context.Background(), i) //nolint:errcheck
+
+	// Wait until it's ACTIVE
+	test.Poll(t, 1*time.Second, ring.ACTIVE, func() interface{} {
+		return i.lifecycler.GetState()
+	})
+
+	i.inflightQueryRequests.Add(1)
+
+	// Mock request
+	ctx := user.InjectOrgID(context.Background(), "test")
+
+	wreq, _ := mockWriteRequest(t, labels.Labels{{Name: labels.MetricName, Value: "test_1"}, {Name: "status", Value: "200"}, {Name: "route", Value: "get_user"}}, 1, 100000)
+	_, err = i.Push(ctx, wreq)
+	require.NoError(t, err)
+
+	rreq := &client.ExemplarQueryRequest{}
+	_, err = i.QueryExemplars(ctx, rreq)
+	require.Error(t, err)
+}
+
 func generateSamplesForLabel(l labels.Labels, count int) *cortexpb.WriteRequest {
 	var lbls = make([]labels.Labels, 0, count)
 	var samples = make([]cortexpb.Sample, 0, count)

pkg/ingester/instance_limits.go

@@ -8,15 +8,17 @@ var (
 	errMaxUsersLimitReached           = errors.New("cannot create TSDB: ingesters's max tenants limit reached")
 	errMaxSeriesLimitReached          = errors.New("cannot add series: ingesters's max series limit reached")
 	errTooManyInflightPushRequests    = errors.New("cannot push: too many inflight push requests in ingester")
+	errTooManyInflightQueryRequests   = errors.New("cannot push: too many inflight query requests in ingester")
 )
 
 // InstanceLimits describes limits used by ingester. Reaching any of these will result in Push method to return
 // (internal) error.
 type InstanceLimits struct {
-	MaxIngestionRate        float64 `yaml:"max_ingestion_rate"`
-	MaxInMemoryTenants      int64   `yaml:"max_tenants"`
-	MaxInMemorySeries       int64   `yaml:"max_series"`
-	MaxInflightPushRequests int64   `yaml:"max_inflight_push_requests"`
+	MaxIngestionRate         float64 `yaml:"max_ingestion_rate"`
+	MaxInMemoryTenants       int64   `yaml:"max_tenants"`
+	MaxInMemorySeries        int64   `yaml:"max_series"`
+	MaxInflightPushRequests  int64   `yaml:"max_inflight_push_requests"`
+	MaxInflightQueryRequests int64   `yaml:"max_inflight_query_requests"`
 }
 
 // Sets default limit values for unmarshalling.

pkg/ingester/instance_limits_test.go

@@ -9,10 +9,11 @@ import (
 
 func TestInstanceLimitsUnmarshal(t *testing.T) {
 	defaultInstanceLimits = &InstanceLimits{
-		MaxIngestionRate:        10,
-		MaxInMemoryTenants:      20,
-		MaxInMemorySeries:       30,
-		MaxInflightPushRequests: 40,
+		MaxIngestionRate:         10,
+		MaxInMemoryTenants:       20,
+		MaxInMemorySeries:        30,
+		MaxInflightPushRequests:  40,
+		MaxInflightQueryRequests: 50,
 	}
 
 	l := InstanceLimits{}
@@ -24,6 +25,7 @@ max_tenants: 50000
 	require.NoError(t, yaml.UnmarshalStrict([]byte(input), &l))
 	require.Equal(t, float64(125.678), l.MaxIngestionRate)
 	require.Equal(t, int64(50000), l.MaxInMemoryTenants)
-	require.Equal(t, int64(30), l.MaxInMemorySeries)       // default value
-	require.Equal(t, int64(40), l.MaxInflightPushRequests) // default value
+	require.Equal(t, int64(30), l.MaxInMemorySeries)        // default value
+	require.Equal(t, int64(40), l.MaxInflightPushRequests)  // default value
+	require.Equal(t, int64(50), l.MaxInflightQueryRequests) // default value
 }