fix: errors reported by the race detector

pkg/analytics/reporter.go

@@ -95,28 +95,31 @@ func (rep *Reporter) initLeader(ctx context.Context) *ClusterSeed {
 		MaxRetries: 0,
 	})
 	for backoff.Ongoing() {
-		// create a new cluster seed
-		seed := ClusterSeed{
-			UID:               uuid.NewString(),
-			PrometheusVersion: build.GetVersion(),
-			CreatedAt:         time.Now(),
-		}
-		if err := kvClient.CAS(ctx, seedKey, func(in interface{}) (out interface{}, retry bool, err error) {
-			// The key is already set, so we don't need to do anything
-			if in != nil {
-				if kvSeed, ok := in.(*ClusterSeed); ok && kvSeed != nil && kvSeed.UID != seed.UID {
-					seed = *kvSeed
-					return nil, false, nil
+		{
+			// create a new cluster seed
+			seed := ClusterSeed{
+				UID:               uuid.NewString(),
+				PrometheusVersion: build.GetVersion(),
+				CreatedAt:         time.Now(),
+			}
+			if err := kvClient.CAS(ctx, seedKey, func(in interface{}) (out interface{}, retry bool, err error) {
+				// The key is already set, so we don't need to do anything
+				if in != nil {
+					if kvSeed, ok := in.(*ClusterSeed); ok && kvSeed != nil && kvSeed.UID != seed.UID {
+						seed = *kvSeed
+						return nil, false, nil
+					}
 				}
+				return &seed, true, nil
+			}); err != nil {
+				level.Info(rep.logger).Log("msg", "failed to CAS cluster seed key", "err", err)
+				continue
 			}
-			return &seed, true, nil
-		}); err != nil {
-			level.Info(rep.logger).Log("msg", "failed to CAS cluster seed key", "err", err)
-			continue
 		}
 		// ensure stability of the cluster seed
 		stableSeed := ensureStableKey(ctx, kvClient, rep.logger)
-		seed = *stableSeed
+		// This is a new local variable so that Go knows it's not racing with the previous usage.
+		seed := *stableSeed
 		// Fetch the remote cluster seed.
 		remoteSeed, err := rep.fetchSeed(ctx,
 			func(err error) bool {
@@ -262,7 +265,7 @@ func (rep *Reporter) running(ctx context.Context) error {
 		}
 		return nil
 	}
-	rep.startCPUPercentCollection(ctx)
+	rep.startCPUPercentCollection(ctx, time.Minute)
 	// check every minute if we should report.
 	ticker := time.NewTicker(reportCheckInterval)
 	defer ticker.Stop()
@@ -317,13 +320,13 @@ func (rep *Reporter) reportUsage(ctx context.Context, interval time.Time) error
 	return errs.Err()
 }
 
+const cpuUsageKey = "cpu_usage"
+
 var (
-	cpuUsageKey           = "cpu_usage"
-	cpuUsage              = NewFloat(cpuUsageKey)
-	cpuCollectionInterval = time.Minute
+	cpuUsage = NewFloat(cpuUsageKey)
 )
 
-func (rep *Reporter) startCPUPercentCollection(ctx context.Context) {
+func (rep *Reporter) startCPUPercentCollection(ctx context.Context, cpuCollectionInterval time.Duration) {
 	proc, err := process.NewProcess(int32(os.Getpid()))
 	if err != nil {
 		level.Debug(rep.logger).Log("msg", "failed to get process", "err", err)

pkg/analytics/reporter_test.go

@@ -159,14 +159,13 @@ func TestWrongKV(t *testing.T) {
 }
 
 func TestStartCPUCollection(t *testing.T) {
-	cpuCollectionInterval = 1 * time.Second
 	r, err := NewReporter(Config{Leader: true, Enabled: true}, kv.Config{
 		Store: "inmemory",
 	}, nil, log.NewLogfmtLogger(os.Stdout), prometheus.NewPedanticRegistry())
 	require.NoError(t, err)
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	r.startCPUPercentCollection(ctx)
+	r.startCPUPercentCollection(ctx, 1*time.Second)
 	require.Eventually(t, func() bool {
 		return cpuUsage.Value() > 0
 	}, 5*time.Second, 1*time.Second)

pkg/bloombuild/builder/builder_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/model"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/atomic"
 	"google.golang.org/grpc"
 
 	"github.com/grafana/loki/v3/pkg/bloombuild/protos"
@@ -87,7 +88,7 @@ func Test_BuilderLoop(t *testing.T) {
 	require.NoError(t, err)
 
 	require.Eventually(t, func() bool {
-		return server.completedTasks == len(tasks)
+		return int(server.completedTasks.Load()) == len(tasks)
 	}, 5*time.Second, 100*time.Millisecond)
 
 	err = services.StopAndAwaitTerminated(context.Background(), builder)
@@ -98,7 +99,7 @@ func Test_BuilderLoop(t *testing.T) {
 
 type fakePlannerServer struct {
 	tasks          []*protos.ProtoTask
-	completedTasks int
+	completedTasks atomic.Int64
 	shutdownCalled bool
 
 	addr       string
@@ -148,7 +149,7 @@ func (f *fakePlannerServer) BuilderLoop(srv protos.PlannerForBuilder_BuilderLoop
 		if _, err := srv.Recv(); err != nil {
 			return fmt.Errorf("failed to receive task response: %w", err)
 		}
-		f.completedTasks++
+		f.completedTasks.Add(1)
 	}
 
 	// No more tasks. Wait until shutdown.

pkg/bloombuild/planner/planner.go

@@ -701,7 +701,7 @@ func (p *Planner) totalPendingTasks() (total int) {
 func (p *Planner) enqueueTask(task *QueueTask) error {
 	p.activeUsers.UpdateUserTimestamp(task.Tenant, time.Now())
 	return p.tasksQueue.Enqueue(task.Tenant, nil, task, func() {
-		task.timesEnqueued++
+		task.timesEnqueued.Add(1)
 		p.addPendingTask(task)
 	})
 }
@@ -761,12 +761,12 @@ func (p *Planner) BuilderLoop(builder protos.PlannerForBuilder_BuilderLoopServer
 		result, err := p.forwardTaskToBuilder(builder, builderID, task)
 		if err != nil {
 			maxRetries := p.limits.BloomTaskMaxRetries(task.Tenant)
-			if maxRetries > 0 && task.timesEnqueued >= maxRetries {
+			if maxRetries > 0 && int(task.timesEnqueued.Load()) >= maxRetries {
 				p.metrics.tasksFailed.Inc()
 				p.removePendingTask(task)
 				level.Error(logger).Log(
 					"msg", "task failed after max retries",
-					"retries", task.timesEnqueued,
+					"retries", task.timesEnqueued.Load(),
 					"maxRetries", maxRetries,
 					"err", err,
 				)
@@ -792,7 +792,7 @@ func (p *Planner) BuilderLoop(builder protos.PlannerForBuilder_BuilderLoopServer
 			p.metrics.tasksRequeued.Inc()
 			level.Error(logger).Log(
 				"msg", "error forwarding task to builder, Task requeued",
-				"retries", task.timesEnqueued,
+				"retries", task.timesEnqueued.Load(),
 				"err", err,
 			)
 			continue
@@ -801,7 +801,7 @@ func (p *Planner) BuilderLoop(builder protos.PlannerForBuilder_BuilderLoopServer
 		level.Debug(logger).Log(
 			"msg", "task completed",
 			"duration", time.Since(task.queueTime).Seconds(),
-			"retries", task.timesEnqueued,
+			"retries", task.timesEnqueued.Load(),
 		)
 		p.removePendingTask(task)
 

pkg/bloombuild/planner/planner_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/model"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/atomic"
 	"google.golang.org/grpc"
 
 	"github.com/grafana/loki/v3/pkg/bloombuild/protos"
@@ -517,7 +518,7 @@ func Test_BuilderLoop(t *testing.T) {
 			resultsCh := make(chan *protos.TaskResult, nTasks)
 			tasks := createTasks(nTasks, resultsCh)
 			for _, task := range tasks {
-				err = planner.enqueueTask(task)
+				err := planner.enqueueTask(task)
 				require.NoError(t, err)
 			}
 
@@ -527,10 +528,10 @@ func Test_BuilderLoop(t *testing.T) {
 				builder := newMockBuilder(fmt.Sprintf("builder-%d", i))
 				builders = append(builders, builder)
 
-				go func() {
-					err = planner.BuilderLoop(builder)
-					require.ErrorIs(t, err, tc.expectedBuilderLoopError)
-				}()
+				go func(expectedBuilderLoopError error) {
+					err := planner.BuilderLoop(builder)
+					require.ErrorIs(t, err, expectedBuilderLoopError)
+				}(tc.expectedBuilderLoopError)
 			}
 
 			// Eventually, all tasks should be sent to builders
@@ -558,7 +559,7 @@ func Test_BuilderLoop(t *testing.T) {
 
 				// Enqueue tasks again
 				for _, task := range tasks {
-					err = planner.enqueueTask(task)
+					err := planner.enqueueTask(task)
 					require.NoError(t, err)
 				}
 
@@ -809,14 +810,15 @@ func Test_processTenantTaskResults(t *testing.T) {
 }
 
 type fakeBuilder struct {
+	mx          sync.Mutex // Protects tasks and currTaskIdx.
 	id          string
 	tasks       []*protos.Task
 	currTaskIdx int
 	grpc.ServerStream
 
-	returnError    bool
-	returnErrorMsg bool
-	wait           bool
+	returnError    atomic.Bool
+	returnErrorMsg atomic.Bool
+	wait           atomic.Bool
 	ctx            context.Context
 	ctxCancel      context.CancelFunc
 }
@@ -833,19 +835,21 @@ func newMockBuilder(id string) *fakeBuilder {
 }
 
 func (f *fakeBuilder) ReceivedTasks() []*protos.Task {
+	f.mx.Lock()
+	defer f.mx.Unlock()
 	return f.tasks
 }
 
 func (f *fakeBuilder) SetReturnError(b bool) {
-	f.returnError = b
+	f.returnError.Store(b)
 }
 
 func (f *fakeBuilder) SetReturnErrorMsg(b bool) {
-	f.returnErrorMsg = b
+	f.returnErrorMsg.Store(b)
 }
 
 func (f *fakeBuilder) SetWait(b bool) {
-	f.wait = b
+	f.wait.Store(b)
 }
 
 func (f *fakeBuilder) CancelContext(b bool) {
@@ -873,6 +877,8 @@ func (f *fakeBuilder) Send(req *protos.PlannerToBuilder) error {
 		return err
 	}
 
+	f.mx.Lock()
+	defer f.mx.Unlock()
 	f.tasks = append(f.tasks, task)
 	f.currTaskIdx++
 	return nil
@@ -886,12 +892,12 @@ func (f *fakeBuilder) Recv() (*protos.BuilderToPlanner, error) {
 		}, nil
 	}
 
-	if f.returnError {
+	if f.returnError.Load() {
 		return nil, fmt.Errorf("fake error from %s", f.id)
 	}
 
 	// Wait until `wait` is false
-	for f.wait {
+	for f.wait.Load() {
 		time.Sleep(time.Second)
 	}
 
@@ -901,10 +907,12 @@ func (f *fakeBuilder) Recv() (*protos.BuilderToPlanner, error) {
 	}
 
 	var errMsg string
-	if f.returnErrorMsg {
+	if f.returnErrorMsg.Load() {
 		errMsg = fmt.Sprintf("fake error from %s", f.id)
 	}
 
+	f.mx.Lock()
+	defer f.mx.Unlock()
 	return &protos.BuilderToPlanner{
 		BuilderID: f.id,
 		Result: protos.ProtoTaskResult{

pkg/bloombuild/planner/task.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"time"
 
+	"go.uber.org/atomic"
+
 	"github.com/grafana/loki/v3/pkg/bloombuild/protos"
 )
 
@@ -13,7 +15,7 @@ type QueueTask struct {
 	resultsChannel chan *protos.TaskResult
 
 	// Tracking
-	timesEnqueued int
+	timesEnqueued atomic.Int64
 	queueTime     time.Time
 	ctx           context.Context
 }

pkg/bloomgateway/bloomgateway_test.go

@@ -140,8 +140,8 @@ func TestBloomGateway_FilterChunkRefs(t *testing.T) {
 	t.Run("request fails when providing invalid block", func(t *testing.T) {
 		now := mktime("2023-10-03 10:00")
 
-		_, metas, queriers, data := createBlocks(t, tenantID, 10, now.Add(-1*time.Hour), now, 0x0000, 0x0fff)
-		mockStore := newMockBloomStore(queriers, metas)
+		refs, metas, queriers, data := createBlocks(t, tenantID, 10, now.Add(-1*time.Hour), now, 0x0000, 0x0fff)
+		mockStore := newMockBloomStore(refs, queriers, metas)
 
 		reg := prometheus.NewRegistry()
 		gw, err := New(cfg, mockStore, logger, reg)
@@ -176,7 +176,7 @@ func TestBloomGateway_FilterChunkRefs(t *testing.T) {
 		now := mktime("2023-10-03 10:00")
 
 		refs, metas, queriers, data := createBlocks(t, tenantID, 10, now.Add(-1*time.Hour), now, 0x0000, 0x0fff)
-		mockStore := newMockBloomStore(queriers, metas)
+		mockStore := newMockBloomStore(refs, queriers, metas)
 		mockStore.err = errors.New("request failed")
 
 		reg := prometheus.NewRegistry()
@@ -220,7 +220,7 @@ func TestBloomGateway_FilterChunkRefs(t *testing.T) {
 
 		// replace store implementation and re-initialize workers and sub-services
 		refs, metas, queriers, data := createBlocks(t, tenantID, 10, now.Add(-1*time.Hour), now, 0x0000, 0x0fff)
-		mockStore := newMockBloomStore(queriers, metas)
+		mockStore := newMockBloomStore(refs, queriers, metas)
 		mockStore.delay = 2000 * time.Millisecond
 
 		reg := prometheus.NewRegistry()
@@ -263,7 +263,7 @@ func TestBloomGateway_FilterChunkRefs(t *testing.T) {
 		now := mktime("2023-10-03 10:00")
 
 		reg := prometheus.NewRegistry()
-		gw, err := New(cfg, newMockBloomStore(nil, nil), logger, reg)
+		gw, err := New(cfg, newMockBloomStore(nil, nil, nil), logger, reg)
 		require.NoError(t, err)
 
 		err = services.StartAndAwaitRunning(context.Background(), gw)
@@ -309,7 +309,7 @@ func TestBloomGateway_FilterChunkRefs(t *testing.T) {
 		now := mktime("2023-10-03 10:00")
 
 		reg := prometheus.NewRegistry()
-		gw, err := New(cfg, newMockBloomStore(nil, nil), logger, reg)
+		gw, err := New(cfg, newMockBloomStore(nil, nil, nil), logger, reg)
 		require.NoError(t, err)
 
 		err = services.StartAndAwaitRunning(context.Background(), gw)
@@ -363,7 +363,7 @@ func TestBloomGateway_FilterChunkRefs(t *testing.T) {
 		refs, metas, queriers, data := createBlocks(t, tenantID, 10, now.Add(-1*time.Hour), now, 0x0000, 0x0fff)
 
 		reg := prometheus.NewRegistry()
-		store := newMockBloomStore(queriers, metas)
+		store := newMockBloomStore(refs, queriers, metas)
 
 		gw, err := New(cfg, store, logger, reg)
 		require.NoError(t, err)