Add metric and enhanced logging for query partial data

CHANGELOG.md

@@ -18,6 +18,7 @@
 * [ENHANCEMENT] Query Frontend: Add a `-frontend.enabled-ruler-query-stats` flag to configure whether to report the query stats log for queries coming from the Ruler. #6504
 * [ENHANCEMENT] OTLP: Support otlp metadata ingestion. #6617
 * [ENHANCEMENT] AlertManager: Add `keep_instance_in_the_ring_on_shutdown` and `tokens_file_path` configs for alertmanager ring. #6628
+* [ENHANCEMENT] Querier: Add metric and enhanced logging for query partial data. #6676
 * [BUGFIX] Ingester: Avoid error or early throttling when READONLY ingesters are present in the ring #6517
 * [BUGFIX] Ingester: Fix labelset data race condition. #6573
 * [BUGFIX] Compactor: Cleaner should not put deletion marker for blocks with no-compact marker. #6576

pkg/distributor/distributor.go

@@ -123,6 +123,7 @@ type Distributor struct {
 	ingesterAppendFailures           *prometheus.CounterVec
 	ingesterQueries                  *prometheus.CounterVec
 	ingesterQueryFailures            *prometheus.CounterVec
+	ingesterPartialDataQueries       prometheus.Counter
 	replicationFactor                prometheus.Gauge
 	latestSeenSampleTimestampPerUser *prometheus.GaugeVec
 
@@ -375,6 +376,11 @@ func New(cfg Config, clientConfig ingester_client.Config, limits *validation.Ove
 			Name:      "distributor_ingester_query_failures_total",
 			Help:      "The total number of failed queries sent to ingesters.",
 		}, []string{"ingester"}),
+		ingesterPartialDataQueries: promauto.With(reg).NewCounter(prometheus.CounterOpts{
+			Namespace: "cortex",
+			Name:      "distributor_ingester_partial_data_queries_total",
+			Help:      "The total number of queries sent to ingesters that may have returned partial data.",
+		}),
 		replicationFactor: promauto.With(reg).NewGauge(prometheus.GaugeOpts{
 			Namespace: "cortex",
 			Name:      "distributor_replication_factor",

pkg/distributor/query.go

@@ -330,7 +330,8 @@ func (d *Distributor) queryIngesterStream(ctx context.Context, replicationSet ri
 	reqStats.AddFetchedSamples(uint64(resp.SamplesCount()))
 
 	if partialdata.IsPartialDataError(err) {
-		level.Info(d.log).Log("msg", "returning partial data")
+		level.Warn(d.log).Log("msg", "returning partial data", "err", err.Error())
+		d.ingesterPartialDataQueries.Inc()
 		return resp, err
 	}
 

pkg/ring/replication_set.go

@@ -2,6 +2,7 @@ package ring
 
 import (
 	"context"
+	"fmt"
 	"sort"
 	"time"
 
@@ -70,39 +71,32 @@ func (r ReplicationSet) Do(ctx context.Context, delay time.Duration, zoneResults
 		}(i, &r.Instances[i])
 	}
 
-	trackerFailed := false
-	cnt := 0
-
-track:
-	for !tracker.succeeded() {
+	for !tracker.succeeded() && !tracker.finished() {
 		select {
 		case res := <-ch:
 			tracker.done(res.instance, res.res, res.err)
 			if res.err != nil {
-				if tracker.failed() {
-					if !partialDataEnabled || tracker.failedInAllZones() {
-						return nil, res.err
-					}
-					trackerFailed = true
+				if tracker.failed() && (!partialDataEnabled || tracker.failedCompletely()) {
+					return nil, res.err
 				}
 
 				// force one of the delayed requests to start
 				if delay > 0 && r.MaxUnavailableZones == 0 {
 					forceStart <- struct{}{}
 				}
 			}
-			cnt++
-			if cnt == len(r.Instances) {
-				break track
-			}
 
 		case <-ctx.Done():
 			return nil, ctx.Err()
 		}
 	}
 
-	if partialDataEnabled && trackerFailed {
-		return tracker.getResults(), partialdata.ErrPartialData
+	if partialDataEnabled && tracker.failed() {
+		finalErr := partialdata.ErrPartialData
+		for _, partialErr := range tracker.getErrors() {
+			finalErr = fmt.Errorf("%w: %w", finalErr, partialErr)
+		}
+		return tracker.getResults(), finalErr
 	}
 
 	return tracker.getResults(), nil

pkg/ring/replication_set_test.go

@@ -124,6 +124,7 @@ func TestReplicationSet_Do(t *testing.T) {
 		expectedError       error
 		zoneResultsQuorum   bool
 		queryPartialData    bool
+		errStrContains      []string
 	}{
 		{
 			name: "max errors = 0, no errors no delay",
@@ -196,12 +197,13 @@ func TestReplicationSet_Do(t *testing.T) {
 		},
 		{
 			name:                "with partial data enabled and max unavailable zones = 1, should succeed on instances failing in 2 out of 3 zones (3 instances)",
-			instances:           []InstanceDesc{{Zone: "zone1"}, {Zone: "zone2"}, {Zone: "zone3"}},
+			instances:           []InstanceDesc{{Addr: "10.0.0.1", Zone: "zone1"}, {Addr: "10.0.0.2", Zone: "zone2"}, {Addr: "10.0.0.3", Zone: "zone3"}},
 			f:                   failingFunctionOnZones("zone1", "zone2"),
 			maxUnavailableZones: 1,
 			queryPartialData:    true,
 			want:                []interface{}{1},
 			expectedError:       partialdata.ErrPartialData,
+			errStrContains:      []string{"10.0.0.1", "10.0.0.2", "zone failed"},
 		},
 		{
 			name:                "with partial data enabled, should fail on instances failing in all zones",
@@ -264,7 +266,10 @@ func TestReplicationSet_Do(t *testing.T) {
 			}
 			got, err := r.Do(ctx, tt.delay, tt.zoneResultsQuorum, tt.queryPartialData, tt.f)
 			if tt.expectedError != nil {
-				assert.Equal(t, tt.expectedError, err)
+				assert.ErrorIs(t, err, tt.expectedError)
+				for _, str := range tt.errStrContains {
+					assert.ErrorContains(t, err, str)
+				}
 			} else {
 				assert.NoError(t, err)
 			}

pkg/ring/replication_set_tracker.go

@@ -1,22 +1,30 @@
 package ring
 
+import "fmt"
+
 type replicationSetResultTracker interface {
 	// Signals an instance has done the execution, either successful (no error)
 	// or failed (with error). If successful, result will be recorded and can
 	// be accessed via getResults.
 	done(instance *InstanceDesc, result interface{}, err error)
 
+	// Returns true if all instances are done executing
+	finished() bool
+
 	// Returns true if the minimum number of successful results have been received.
 	succeeded() bool
 
 	// Returns true if the maximum number of failed executions have been reached.
 	failed() bool
 
-	// Returns true if executions failed in all zones. Only relevant for zoneAwareResultTracker.
-	failedInAllZones() bool
+	// Returns true if executions failed in all instances or all zones.
+	failedCompletely() bool
 
 	// Returns recorded results.
 	getResults() []interface{}
+
+	// Returns errors
+	getErrors() []error
 }
 
 type defaultResultTracker struct {
@@ -25,6 +33,8 @@ type defaultResultTracker struct {
 	numErrors    int
 	maxErrors    int
 	results      []interface{}
+	numInstances int
+	errors       []error
 }
 
 func newDefaultResultTracker(instances []InstanceDesc, maxErrors int) *defaultResultTracker {
@@ -33,19 +43,26 @@ func newDefaultResultTracker(instances []InstanceDesc, maxErrors int) *defaultRe
 		numSucceeded: 0,
 		numErrors:    0,
 		maxErrors:    maxErrors,
+		errors:       make([]error, 0, len(instances)),
 		results:      make([]interface{}, 0, len(instances)),
+		numInstances: len(instances),
 	}
 }
 
-func (t *defaultResultTracker) done(_ *InstanceDesc, result interface{}, err error) {
+func (t *defaultResultTracker) done(instance *InstanceDesc, result interface{}, err error) {
 	if err == nil {
 		t.numSucceeded++
 		t.results = append(t.results, result)
 	} else {
+		t.errors = append(t.errors, fmt.Errorf("(%s) %w", instance.GetAddr(), err))
 		t.numErrors++
 	}
 }
 
+func (t *defaultResultTracker) finished() bool {
+	return t.numSucceeded+t.numErrors == t.numInstances
+}
+
 func (t *defaultResultTracker) succeeded() bool {
 	return t.numSucceeded >= t.minSucceeded
 }
@@ -54,14 +71,18 @@ func (t *defaultResultTracker) failed() bool {
 	return t.numErrors > t.maxErrors
 }
 
-func (t *defaultResultTracker) failedInAllZones() bool {
-	return false
+func (t *defaultResultTracker) failedCompletely() bool {
+	return t.numInstances == t.numErrors
 }
 
 func (t *defaultResultTracker) getResults() []interface{} {
 	return t.results
 }
 
+func (t *defaultResultTracker) getErrors() []error {
+	return t.errors
+}
+
 // zoneAwareResultTracker tracks the results per zone.
 // All instances in a zone must succeed in order for the zone to succeed.
 type zoneAwareResultTracker struct {
@@ -73,6 +94,8 @@ type zoneAwareResultTracker struct {
 	numInstances        int
 	zoneResultsQuorum   bool
 	zoneCount           int
+	doneCount           int
+	errors              []error
 }
 
 func newZoneAwareResultTracker(instances []InstanceDesc, maxUnavailableZones int, zoneResultsQuorum bool) *zoneAwareResultTracker {
@@ -82,6 +105,7 @@ func newZoneAwareResultTracker(instances []InstanceDesc, maxUnavailableZones int
 		maxUnavailableZones: maxUnavailableZones,
 		numInstances:        len(instances),
 		zoneResultsQuorum:   zoneResultsQuorum,
+		errors:              make([]error, 0, len(instances)),
 	}
 
 	for _, instance := range instances {
@@ -97,6 +121,7 @@ func newZoneAwareResultTracker(instances []InstanceDesc, maxUnavailableZones int
 func (t *zoneAwareResultTracker) done(instance *InstanceDesc, result interface{}, err error) {
 	if err != nil {
 		t.failuresByZone[instance.Zone]++
+		t.errors = append(t.errors, fmt.Errorf("(%s) %w", instance.GetAddr(), err))
 	} else {
 		if _, ok := t.resultsPerZone[instance.Zone]; !ok {
 			// If it is the first result in the zone, then total number of instances
@@ -107,6 +132,11 @@ func (t *zoneAwareResultTracker) done(instance *InstanceDesc, result interface{}
 	}
 
 	t.waitingByZone[instance.Zone]--
+	t.doneCount++
+}
+
+func (t *zoneAwareResultTracker) finished() bool {
+	return t.doneCount == t.numInstances
 }
 
 func (t *zoneAwareResultTracker) succeeded() bool {
@@ -128,7 +158,7 @@ func (t *zoneAwareResultTracker) failed() bool {
 	return failedZones > t.maxUnavailableZones
 }
 
-func (t *zoneAwareResultTracker) failedInAllZones() bool {
+func (t *zoneAwareResultTracker) failedCompletely() bool {
 	failedZones := len(t.failuresByZone)
 	return failedZones == t.zoneCount
 }
@@ -150,3 +180,7 @@ func (t *zoneAwareResultTracker) getResults() []interface{} {
 	}
 	return results
 }
+
+func (t *zoneAwareResultTracker) getErrors() []error {
+	return t.errors
+}

pkg/ring/replication_set_tracker_test.go

@@ -2,6 +2,7 @@ package ring
 
 import (
 	"errors"
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -154,6 +155,50 @@ func TestDefaultResultTracker(t *testing.T) {
 				assert.Equal(t, []interface{}{[]int{1, 1, 1}, []int{2, 2, 2}, []int{3, 3, 3}}, tracker.getResults())
 			},
 		},
+		"failedCompletely() should return true only if all instances have failed, regardless of max errors": {
+			instances: []InstanceDesc{instance1, instance2, instance3},
+			maxErrors: 1,
+			run: func(t *testing.T, tracker *defaultResultTracker) {
+				tracker.done(&instance1, nil, errors.New("test"))
+				assert.False(t, tracker.succeeded())
+				assert.False(t, tracker.failed())
+				assert.False(t, tracker.failedCompletely())
+
+				tracker.done(&instance2, nil, errors.New("test"))
+				assert.False(t, tracker.succeeded())
+				assert.True(t, tracker.failed())
+				assert.False(t, tracker.failedCompletely())
+
+				tracker.done(&instance3, nil, errors.New("test"))
+				assert.False(t, tracker.succeeded())
+				assert.True(t, tracker.failed())
+				assert.True(t, tracker.failedCompletely())
+			},
+		},
+		"finished() should return true only if all instances are done": {
+			instances: []InstanceDesc{instance1, instance2},
+			maxErrors: 1,
+			run: func(t *testing.T, tracker *defaultResultTracker) {
+				tracker.done(&instance1, nil, errors.New("test"))
+				assert.False(t, tracker.finished())
+
+				tracker.done(&instance2, nil, errors.New("test"))
+				assert.True(t, tracker.finished())
+			},
+		},
+		"getErrors() should return list of all errors": {
+			instances: []InstanceDesc{instance1, instance2},
+			maxErrors: 1,
+			run: func(t *testing.T, tracker *defaultResultTracker) {
+				tracker.done(&instance1, nil, errors.New("test1"))
+				err1 := fmt.Errorf("(%s) %w", instance1.GetAddr(), errors.New("test1"))
+				assert.ElementsMatch(t, []error{err1}, tracker.getErrors())
+
+				tracker.done(&instance2, nil, errors.New("test2"))
+				err2 := fmt.Errorf("(%s) %w", instance2.GetAddr(), errors.New("test2"))
+				assert.ElementsMatch(t, []error{err1, err2}, tracker.getErrors())
+			},
+		},
 	}
 
 	for testName, testCase := range tests {
@@ -399,27 +444,51 @@ func TestZoneAwareResultTracker(t *testing.T) {
 				assert.False(t, tracker.failed())
 			},
 		},
-		"failInAllZones should return true only if all zones have failed, regardless of max unavailable zones": {
+		"failedCompletely() should return true only if all zones have failed, regardless of max unavailable zones": {
 			instances:           []InstanceDesc{instance1, instance2, instance3, instance4, instance5, instance6},
 			maxUnavailableZones: 1,
 			run: func(t *testing.T, tracker *zoneAwareResultTracker) {
 				// Zone-a
 				tracker.done(&instance1, nil, errors.New("test"))
 				assert.False(t, tracker.succeeded())
 				assert.False(t, tracker.failed())
-				assert.False(t, tracker.failedInAllZones())
+				assert.False(t, tracker.failedCompletely())
 
 				// Zone-b
 				tracker.done(&instance3, nil, errors.New("test"))
 				assert.False(t, tracker.succeeded())
 				assert.True(t, tracker.failed())
-				assert.False(t, tracker.failedInAllZones())
+				assert.False(t, tracker.failedCompletely())
 
 				// Zone-c
 				tracker.done(&instance5, nil, errors.New("test"))
 				assert.False(t, tracker.succeeded())
 				assert.True(t, tracker.failed())
-				assert.True(t, tracker.failedInAllZones())
+				assert.True(t, tracker.failedCompletely())
+			},
+		},
+		"finished() should return true only if all instances are done": {
+			instances:           []InstanceDesc{instance1, instance2},
+			maxUnavailableZones: 1,
+			run: func(t *testing.T, tracker *zoneAwareResultTracker) {
+				tracker.done(&instance1, nil, errors.New("test"))
+				assert.False(t, tracker.finished())
+
+				tracker.done(&instance2, nil, errors.New("test"))
+				assert.True(t, tracker.finished())
+			},
+		},
+		"getErrors() should return list of all errors": {
+			instances:           []InstanceDesc{instance1, instance2},
+			maxUnavailableZones: 1,
+			run: func(t *testing.T, tracker *zoneAwareResultTracker) {
+				tracker.done(&instance1, nil, errors.New("test1"))
+				err1 := fmt.Errorf("(%s) %w", instance1.GetAddr(), errors.New("test1"))
+				assert.ElementsMatch(t, []error{err1}, tracker.getErrors())
+
+				tracker.done(&instance2, nil, errors.New("test2"))
+				err2 := fmt.Errorf("(%s) %w", instance2.GetAddr(), errors.New("test2"))
+				assert.ElementsMatch(t, []error{err1, err2}, tracker.getErrors())
 			},
 		},
 	}