Separate interface

common/metrics/metrics.go

@@ -60,9 +60,14 @@ type (
 
 		Stop(log.Logger)
 
-		// BatchStart returns a Handler that where supported, can emit a series of metrics as a single "wide event".
+		// StartBatch returns a BatchHandler that can emit a series of metrics as a single "wide event".
 		// If wide events aren't supported in the underlying implementation, metrics can still be sent individually.
-		BatchStart(string) (Handler, io.Closer)
+		StartBatch(string) BatchHandler
+	}
+
+	BatchHandler interface {
+		Handler
+		io.Closer
 	}
 
 	// CounterIface is an ever-increasing counter.
@@ -71,7 +76,7 @@ type (
 		// Tags provided are merged with the source MetricsHandler
 		Record(int64, ...Tag)
 	}
-	// GaugeIface can be set to any float and repesents a latest value instrument.
+	// GaugeIface can be set to any float and represents a latest value instrument.
 	GaugeIface interface {
 		// Record updates the gauge value.
 		// Tags provided are merged with the source MetricsHandler

common/metrics/metricstest/capture_handler.go

@@ -25,7 +25,6 @@
 package metricstest
 
 import (
-	"io"
 	"sync"
 	"time"
 
@@ -147,8 +146,8 @@ func (c *CaptureHandler) Close() error {
 	return nil
 }
 
-func (c *CaptureHandler) BatchStart(_ string) (metrics.Handler, io.Closer) {
-	return c, c
+func (c *CaptureHandler) StartBatch(_ string) metrics.BatchHandler {
+	return c
 }
 
 // Stop implements [metrics.Handler.Stop].

common/metrics/noop_impl.go

@@ -25,7 +25,6 @@
 package metrics
 
 import (
-	"io"
 	"time"
 
 	"go.temporal.io/server/common/log"
@@ -73,8 +72,8 @@ func (*noopMetricsHandler) Close() error {
 	return nil
 }
 
-func (n *noopMetricsHandler) BatchStart(_ string) (Handler, io.Closer) {
-	return n, n
+func (n *noopMetricsHandler) StartBatch(_ string) BatchHandler {
+	return n
 }
 
 var NoopCounterMetricFunc = CounterFunc(func(i int64, t ...Tag) {})

common/metrics/otel_metrics_handler.go

@@ -27,7 +27,6 @@ package metrics
 import (
 	"context"
 	"fmt"
-	"io"
 	"sync"
 	"time"
 
@@ -209,8 +208,8 @@ func (omp *otelMetricsHandler) Close() error {
 	return nil
 }
 
-func (omp *otelMetricsHandler) BatchStart(_ string) (Handler, io.Closer) {
-	return omp, omp
+func (omp *otelMetricsHandler) StartBatch(_ string) BatchHandler {
+	return omp
 }
 
 // makeSet returns an otel attribute.Set with the given tags merged with the

common/metrics/tally_metrics_handler.go

@@ -25,7 +25,6 @@
 package metrics
 
 import (
-	"io"
 	"time"
 
 	"github.com/uber-go/tally/v4"
@@ -125,8 +124,8 @@ func (*tallyMetricsHandler) Close() error {
 	return nil
 }
 
-func (tmh *tallyMetricsHandler) BatchStart(_ string) (Handler, io.Closer) {
-	return tmh, tmh
+func (tmh *tallyMetricsHandler) StartBatch(_ string) BatchHandler {
+	return tmh
 }
 
 func tagsToMap(t1 []Tag, e excludeTags) map[string]string {

service/history/historybuilder/history_builder_categorization_test.go

@@ -25,7 +25,6 @@
 package historybuilder
 
 import (
-	"io"
 	"testing"
 	"time"
 
@@ -71,8 +70,8 @@ func (h StubHandler) Close() error {
 	return nil
 }
 
-func (h StubHandler) BatchStart(_ string) (metrics.Handler, io.Closer) {
-	return h, h
+func (h StubHandler) StartBatch(_ string) metrics.BatchHandler {
+	return h
 }
 
 func TestHistoryBuilder_IsDirty(t *testing.T) {

service/history/workflow/metrics.go

@@ -61,8 +61,8 @@ func emitMutableStateStatus(
 		return
 	}
 
-	batchHandler, closer := metricsHandler.BatchStart("mutable_state_status")
-	defer closer.Close()
+	batchHandler := metricsHandler.StartBatch("mutable_state_status")
+	defer batchHandler.Close()
 	metrics.MutableStateSize.With(batchHandler).Record(int64(stats.TotalSize))
 	metrics.ExecutionInfoSize.With(batchHandler).Record(int64(stats.ExecutionInfoSize))
 	metrics.ExecutionStateSize.With(batchHandler).Record(int64(stats.ExecutionStateSize))