Merge pull request #1678 from authzed/decorate-spans

decorate check dispatch spans with caching and singleflight attributes
authzed · Dec 11, 2023 · 01c462b · 01c462b
2 parents a6ea7a3 + 723e94e
commit 01c462b
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Showing 4 changed files with 15 additions and 3 deletions.
diff --git a/go.mod b/go.mod
@@ -89,7 +89,7 @@ require (
 	google.golang.org/protobuf v1.31.0
 	gopkg.in/yaml.v2 v2.4.0
 	gopkg.in/yaml.v3 v3.0.1
-	resenje.org/singleflight v0.4.0
+	resenje.org/singleflight v0.4.1
 	sigs.k8s.io/controller-runtime v0.16.2
 )
 

diff --git a/go.sum b/go.sum
@@ -1454,8 +1454,8 @@ mvdan.cc/lint v0.0.0-20170908181259-adc824a0674b h1:DxJ5nJdkhDlLok9K6qO+5290kphD
 mvdan.cc/lint v0.0.0-20170908181259-adc824a0674b/go.mod h1:2odslEg/xrtNQqCYg2/jCoyKnw3vv5biOc3JnIcYfL4=
 mvdan.cc/unparam v0.0.0-20230312165513-e84e2d14e3b8 h1:VuJo4Mt0EVPychre4fNlDWDuE5AjXtPJpRUWqZDQhaI=
 mvdan.cc/unparam v0.0.0-20230312165513-e84e2d14e3b8/go.mod h1:Oh/d7dEtzsNHGOq1Cdv8aMm3KdKhVvPbRQcM8WFpBR8=
-resenje.org/singleflight v0.4.0 h1:NdOEhCxEikK2S2WxGjZV9EGSsItolQKslOOi6pE1tJc=
-resenje.org/singleflight v0.4.0/go.mod h1:lAgQK7VfjG6/pgredbQfmV0RvG/uVhKo6vSuZ0vCWfk=
+resenje.org/singleflight v0.4.1 h1:ryGHRaOBwhnZLyf34LMDf4AsTSHrs4hdGPdG/I4Hmac=
+resenje.org/singleflight v0.4.1/go.mod h1:lAgQK7VfjG6/pgredbQfmV0RvG/uVhKo6vSuZ0vCWfk=
 rsc.io/binaryregexp v0.2.0/go.mod h1:qTv7/COck+e2FymRvadv62gMdZztPaShugOCi3I+8D8=
 rsc.io/quote/v3 v3.1.0/go.mod h1:yEA65RcK8LyAZtP9Kv3t0HmxON59tX3rD+tICJqUlj0=
 rsc.io/sampler v1.3.0/go.mod h1:T1hPZKmBbMNahiBKFy5HrXp6adAjACjK9JXDnKaTXpA=

diff --git a/internal/dispatch/caching/caching.go b/internal/dispatch/caching/caching.go
@@ -11,6 +11,8 @@ import (
 	"github.com/dustin/go-humanize"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
 
 	"github.com/authzed/spicedb/internal/dispatch"
 	"github.com/authzed/spicedb/internal/dispatch/keys"
@@ -169,6 +171,7 @@ func (cd *Dispatcher) DispatchCheck(ctx context.Context, req *v1.DispatchCheckRe
 	}
 
 	// Disable caching when debugging is enabled.
+	span := trace.SpanFromContext(ctx)
 	if cachedResultRaw, found := cd.c.Get(requestKey); found {
 		var response v1.DispatchCheckResponse
 		if err := response.UnmarshalVT(cachedResultRaw.([]byte)); err != nil {
@@ -188,9 +191,11 @@ func (cd *Dispatcher) DispatchCheck(ctx context.Context, req *v1.DispatchCheckRe
 				}
 			}
 
+			span.SetAttributes(attribute.Bool("cached", true))
 			return &response, nil
 		}
 	}
+	span.SetAttributes(attribute.Bool("cached", false))
 	computed, err := cd.d.DispatchCheck(ctx, req)
 
 	// We only want to cache the result if there was no error

diff --git a/internal/dispatch/singleflight/singleflight.go b/internal/dispatch/singleflight/singleflight.go
@@ -8,6 +8,8 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 	"resenje.org/singleflight"
@@ -80,7 +82,9 @@ func (d *Dispatcher) DispatchCheck(ctx context.Context, req *v1.DispatchCheckReq
 		return d.delegate.DispatchCheck(ctx, req)
 	}
 
+	primary := false
 	v, isShared, err := d.checkGroup.Do(ctx, keyString, func(innerCtx context.Context) (*v1.DispatchCheckResponse, error) {
+		primary = true
 		return d.delegate.DispatchCheck(innerCtx, req)
 	})
 
@@ -89,6 +93,9 @@ func (d *Dispatcher) DispatchCheck(ctx context.Context, req *v1.DispatchCheckReq
 		return &v1.DispatchCheckResponse{Metadata: &v1.ResponseMeta{DispatchCount: 1}}, err
 	}
 
+	span := trace.SpanFromContext(ctx)
+	singleflighted := isShared && !primary
+	span.SetAttributes(attribute.Bool("singleflight", singleflighted))
 	return v, err
 }