Merge pull request #17499 from influxdata/feature/move-prometheus-span

chore(tracing): Span with Prometheus Metrics moved to kit/tracing

kit/tracing/tracing.go

@@ -6,7 +6,9 @@ import (
 	"net/http"
 	"runtime"
 	"strings"
+	"time"
 
+	"github.com/prometheus/client_golang/prometheus"
 	"github.com/uber/jaeger-client-go"
 
 	"github.com/influxdata/httprouter"
@@ -75,6 +77,33 @@ func annotateSpan(span opentracing.Span, handlerName string, req *http.Request)
 	span.LogKV("path", req.URL.Path)
 }
 
+// span is a simple wrapper around opentracing.Span in order to
+// get access to the duration of the span for metrics reporting.
+type Span struct {
+	opentracing.Span
+	start    time.Time
+	Duration time.Duration
+	hist     prometheus.Observer
+	gauge    prometheus.Gauge
+}
+
+func StartSpanFromContextWithPromMetrics(ctx context.Context, operationName string, hist prometheus.Observer, gauge prometheus.Gauge, opts ...opentracing.StartSpanOption) (*Span, context.Context) {
+	start := time.Now()
+	s, sctx := StartSpanFromContextWithOperationName(ctx, operationName, opentracing.StartTime(start))
+	gauge.Inc()
+	return &Span{s, start, 0, hist, gauge}, sctx
+}
+
+func (s *Span) Finish() {
+	finish := time.Now()
+	s.Duration = finish.Sub(s.start)
+	s.Span.FinishWithOptions(opentracing.FinishOptions{
+		FinishTime: finish,
+	})
+	s.hist.Observe(s.Duration.Seconds())
+	s.gauge.Dec()
+}
+
 // StartSpanFromContext is an improved opentracing.StartSpanFromContext.
 // Uses the calling function as the operation name, and logs the filename and line number.
 //
@@ -100,7 +129,7 @@ func annotateSpan(span opentracing.Span, handlerName string, req *http.Request)
 //
 //  // Sugar to create a child span
 //  span, ctx := opentracing.StartSpanFromContext(ctx, "operation name")
-func StartSpanFromContext(ctx context.Context) (opentracing.Span, context.Context) {
+func StartSpanFromContext(ctx context.Context, opts ...opentracing.StartSpanOption) (opentracing.Span, context.Context) {
 	if ctx == nil {
 		panic("StartSpanFromContext called with nil context")
 	}
@@ -109,7 +138,7 @@ func StartSpanFromContext(ctx context.Context) (opentracing.Span, context.Contex
 	var pcs [1]uintptr
 	n := runtime.Callers(2, pcs[:])
 	if n < 1 {
-		span, ctx := opentracing.StartSpanFromContext(ctx, "unknown")
+		span, ctx := opentracing.StartSpanFromContext(ctx, "unknown", opts...)
 		span.LogFields(log.Error(errors.New("runtime.Callers failed")))
 		return span, ctx
 	}
@@ -122,7 +151,8 @@ func StartSpanFromContext(ctx context.Context) (opentracing.Span, context.Contex
 	var span opentracing.Span
 	if parentSpan := opentracing.SpanFromContext(ctx); parentSpan != nil {
 		// Create a child span.
-		span = opentracing.StartSpan(name, opentracing.ChildOf(parentSpan.Context()))
+		opts = append(opts, opentracing.ChildOf(parentSpan.Context()))
+		span = opentracing.StartSpan(name, opts...)
 	} else {
 		// Create a root span.
 		span = opentracing.StartSpan(name)
@@ -137,7 +167,7 @@ func StartSpanFromContext(ctx context.Context) (opentracing.Span, context.Contex
 }
 
 // StartSpanFromContextWithOperationName is like StartSpanFromContext, but the caller determines the operation name.
-func StartSpanFromContextWithOperationName(ctx context.Context, operationName string) (opentracing.Span, context.Context) {
+func StartSpanFromContextWithOperationName(ctx context.Context, operationName string, opts ...opentracing.StartSpanOption) (opentracing.Span, context.Context) {
 	if ctx == nil {
 		panic("StartSpanFromContextWithOperationName called with nil context")
 	}
@@ -146,7 +176,7 @@ func StartSpanFromContextWithOperationName(ctx context.Context, operationName st
 	var pcs [1]uintptr
 	n := runtime.Callers(2, pcs[:])
 	if n < 1 {
-		span, ctx := opentracing.StartSpanFromContext(ctx, operationName)
+		span, ctx := opentracing.StartSpanFromContext(ctx, operationName, opts...)
 		span.LogFields(log.Error(errors.New("runtime.Callers failed")))
 		return span, ctx
 	}
@@ -154,11 +184,12 @@ func StartSpanFromContextWithOperationName(ctx context.Context, operationName st
 
 	var span opentracing.Span
 	if parentSpan := opentracing.SpanFromContext(ctx); parentSpan != nil {
+		opts = append(opts, opentracing.ChildOf(parentSpan.Context()))
 		// Create a child span.
-		span = opentracing.StartSpan(operationName, opentracing.ChildOf(parentSpan.Context()))
+		span = opentracing.StartSpan(operationName, opts...)
 	} else {
 		// Create a root span.
-		span = opentracing.StartSpan(operationName)
+		span = opentracing.StartSpan(operationName, opts...)
 	}
 	// New context references this span, not the parent (if there was one).
 	ctx = opentracing.ContextWithSpan(ctx, span)

query/control/controller.go

@@ -23,7 +23,6 @@ import (
 	"runtime/debug"
 	"sync"
 	"sync/atomic"
-	"time"
 
 	"github.com/influxdata/flux"
 	"github.com/influxdata/flux/codes"
@@ -35,7 +34,6 @@ import (
 	"github.com/influxdata/influxdb/kit/tracing"
 	influxlogger "github.com/influxdata/influxdb/logger"
 	"github.com/influxdata/influxdb/query"
-	"github.com/opentracing/opentracing-go"
 	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
@@ -265,7 +263,7 @@ func (c *Controller) createQuery(ctx context.Context, ct flux.CompilerType) (*Qu
 	compileLabelValues[len(compileLabelValues)-1] = string(ct)
 
 	cctx, cancel := context.WithCancel(ctx)
-	parentSpan, parentCtx := StartSpanFromContext(
+	parentSpan, parentCtx := tracing.StartSpanFromContextWithPromMetrics(
 		cctx,
 		"all",
 		c.metrics.allDur.WithLabelValues(labelValues...),
@@ -535,7 +533,7 @@ type Query struct {
 	cancel      func()
 
 	parentCtx               context.Context
-	parentSpan, currentSpan *span
+	parentSpan, currentSpan *tracing.Span
 	stats                   flux.Statistics
 
 	done   sync.Once
@@ -762,7 +760,7 @@ TRANSITION:
 		return q.parentCtx, true
 	}
 	var currentCtx context.Context
-	q.currentSpan, currentCtx = StartSpanFromContext(
+	q.currentSpan, currentCtx = tracing.StartSpanFromContextWithPromMetrics(
 		q.parentCtx,
 		newState.String(),
 		dur.WithLabelValues(labelValues...),
@@ -977,38 +975,6 @@ func isFinishedState(state State) bool {
 	}
 }
 
-// span is a simple wrapper around opentracing.Span in order to
-// get access to the duration of the span for metrics reporting.
-type span struct {
-	s        opentracing.Span
-	start    time.Time
-	Duration time.Duration
-	hist     prometheus.Observer
-	gauge    prometheus.Gauge
-}
-
-func StartSpanFromContext(ctx context.Context, operationName string, hist prometheus.Observer, gauge prometheus.Gauge) (*span, context.Context) {
-	start := time.Now()
-	s, sctx := opentracing.StartSpanFromContext(ctx, operationName, opentracing.StartTime(start))
-	gauge.Inc()
-	return &span{
-		s:     s,
-		start: start,
-		hist:  hist,
-		gauge: gauge,
-	}, sctx
-}
-
-func (s *span) Finish() {
-	finish := time.Now()
-	s.Duration = finish.Sub(s.start)
-	s.s.FinishWithOptions(opentracing.FinishOptions{
-		FinishTime: finish,
-	})
-	s.hist.Observe(s.Duration.Seconds())
-	s.gauge.Dec()
-}
-
 // handleFluxError will take a flux.Error and convert it into an influxdb.Error.
 // It will match certain codes to the equivalent in influxdb.
 //