Add env support for batch span processor (#2515)

* Add env support for batch span processor

* Update changelog

* lint

CHANGELOG.md

@@ -12,6 +12,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 - Support `OTEL_EXPORTER_ZIPKIN_ENDPOINT` env to specify zipkin collector endpoint (#2490)
 - Log the configuration of TracerProviders, and Tracers for debugging. To enable use a logger with Verbosity (V level) >=1
+- Added environment variables for: `OTEL_BSP_SCHEDULE_DELAY`, `OTEL_BSP_EXPORT_TIMEOUT`, `OTEL_BSP_MAX_QUEUE_SIZE` and `OTEL_BSP_MAX_EXPORT_BATCH_SIZE` (#2515)
 
 ### Changed
 

sdk/trace/batch_span_processor.go

@@ -29,8 +29,8 @@ import (
 // Defaults for BatchSpanProcessorOptions.
 const (
 	DefaultMaxQueueSize       = 2048
-	DefaultBatchTimeout       = 5000 * time.Millisecond
+	DefaultScheduleDelay      = 5000
-	DefaultExportTimeout      = 30000 * time.Millisecond
+	DefaultExportTimeout      = 30000
 	DefaultMaxExportBatchSize = 512
 )
 
@@ -89,11 +89,22 @@ var _ SpanProcessor = (*batchSpanProcessor)(nil)
 //
 // If the exporter is nil, the span processor will preform no action.
 func NewBatchSpanProcessor(exporter SpanExporter, options ...BatchSpanProcessorOption) SpanProcessor {
+	maxQueueSize := intEnvOr(EnvBatchSpanProcessorMaxQueueSize, DefaultMaxQueueSize)
+	maxExportBatchSize := intEnvOr(EnvBatchSpanProcessorMaxExportBatchSize, DefaultMaxExportBatchSize)
+
+	if maxExportBatchSize > maxQueueSize {
+		if DefaultMaxExportBatchSize > maxQueueSize {
+			maxExportBatchSize = maxQueueSize
+		} else {
+			maxExportBatchSize = DefaultMaxExportBatchSize
+		}
+	}
+
 	o := BatchSpanProcessorOptions{
-		BatchTimeout:       DefaultBatchTimeout,
+		BatchTimeout:       time.Duration(intEnvOr(EnvBatchSpanProcessorScheduleDelay, DefaultScheduleDelay)) * time.Millisecond,
-		ExportTimeout:      DefaultExportTimeout,
+		ExportTimeout:      time.Duration(intEnvOr(EnvBatchSpanProcessorExportTimeout, DefaultExportTimeout)) * time.Millisecond,
-		MaxQueueSize:       DefaultMaxQueueSize,
+		MaxQueueSize:       maxQueueSize,
-		MaxExportBatchSize: DefaultMaxExportBatchSize,
+		MaxExportBatchSize: maxExportBatchSize,
 	}
 	for _, opt := range options {
 		opt(&o)

sdk/trace/batch_span_processor_test.go

@@ -19,10 +19,13 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
+	"os"
 	"sync"
 	"testing"
 	"time"
 
+	ottest "go.opentelemetry.io/otel/internal/internaltest"
+
 	"github.com/go-logr/logr/funcr"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -115,6 +118,7 @@ type testOption struct {
 	wantBatchCount int
 	genNumSpans    int
 	parallel       bool
+	envs           map[string]string
 }
 
 func TestNewBatchSpanProcessorWithOptions(t *testing.T) {
@@ -221,6 +225,85 @@ func TestNewBatchSpanProcessorWithOptions(t *testing.T) {
 	}
 }
 
+func TestNewBatchSpanProcessorWithEnvOptions(t *testing.T) {
+	options := []testOption{
+		{
+			name:           "BatchSpanProcessorEnvOptions - Basic",
+			wantNumSpans:   2053,
+			wantBatchCount: 1,
+			genNumSpans:    2053,
+			envs: map[string]string{
+				sdktrace.EnvBatchSpanProcessorMaxQueueSize:       "5000",
+				sdktrace.EnvBatchSpanProcessorMaxExportBatchSize: "5000",
+			},
+		},
+		{
+			name:           "BatchSpanProcessorEnvOptions - A lager max export batch size than queue size",
+			wantNumSpans:   2053,
+			wantBatchCount: 4,
+			genNumSpans:    2053,
+			envs: map[string]string{
+				sdktrace.EnvBatchSpanProcessorMaxQueueSize:       "5000",
+				sdktrace.EnvBatchSpanProcessorMaxExportBatchSize: "10000",
+			},
+		},
+		{
+			name:           "BatchSpanProcessorEnvOptions - A lage max export batch size with a small queue size",
+			wantNumSpans:   2053,
+			wantBatchCount: 42,
+			genNumSpans:    2053,
+			envs: map[string]string{
+				sdktrace.EnvBatchSpanProcessorMaxQueueSize:       "50",
+				sdktrace.EnvBatchSpanProcessorMaxExportBatchSize: "10000",
+			},
+		},
+	}
+
+	envStore := ottest.NewEnvStore()
+	envStore.Record(sdktrace.EnvBatchSpanProcessorScheduleDelay)
+	envStore.Record(sdktrace.EnvBatchSpanProcessorExportTimeout)
+	envStore.Record(sdktrace.EnvBatchSpanProcessorMaxQueueSize)
+	envStore.Record(sdktrace.EnvBatchSpanProcessorMaxExportBatchSize)
+
+	defer func() {
+		require.NoError(t, envStore.Restore())
+	}()
+
+	for _, option := range options {
+		t.Run(option.name, func(t *testing.T) {
+			for k, v := range option.envs {
+				require.NoError(t, os.Setenv(k, v))
+			}
+
+			te := testBatchExporter{}
+			tp := basicTracerProvider(t)
+			ssp := createAndRegisterBatchSP(option, &te)
+			if ssp == nil {
+				t.Fatalf("%s: Error creating new instance of BatchSpanProcessor\n", option.name)
+			}
+			tp.RegisterSpanProcessor(ssp)
+			tr := tp.Tracer("BatchSpanProcessorWithOptions")
+
+			generateSpan(t, option.parallel, tr, option)
+
+			tp.UnregisterSpanProcessor(ssp)
+
+			gotNumOfSpans := te.len()
+			if option.wantNumSpans > 0 && option.wantNumSpans != gotNumOfSpans {
+				t.Errorf("number of exported span: got %+v, want %+v\n",
+					gotNumOfSpans, option.wantNumSpans)
+			}
+
+			gotBatchCount := te.getBatchCount()
+			if option.wantBatchCount > 0 && gotBatchCount < option.wantBatchCount {
+				t.Errorf("number batches: got %+v, want >= %+v\n",
+					gotBatchCount, option.wantBatchCount)
+				t.Errorf("Batches %v\n", te.sizes)
+			}
+		})
+	}
+}
+
 type stuckExporter struct {
 	testBatchExporter
 }

sdk/trace/env.go

@@ -0,0 +1,59 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace // import "go.opentelemetry.io/otel/sdk/trace"
+
+import (
+	"os"
+	"strconv"
+
+	"go.opentelemetry.io/otel/internal/global"
+)
+
+// Environment variable names
+const (
+	// EnvBatchSpanProcessorScheduleDelay
+	// Delay interval between two consecutive exports.
+	// i.e. 5000
+	EnvBatchSpanProcessorScheduleDelay = "OTEL_BSP_SCHEDULE_DELAY"
+	// EnvBatchSpanProcessorExportTimeout
+	// Maximum allowed time to export data.
+	// i.e. 3000
+	EnvBatchSpanProcessorExportTimeout = "OTEL_BSP_EXPORT_TIMEOUT"
+	// EnvBatchSpanProcessorMaxQueueSize
+	// Maximum queue size
+	// i.e. 2048
+	EnvBatchSpanProcessorMaxQueueSize = "OTEL_BSP_MAX_QUEUE_SIZE"
+	// EnvBatchSpanProcessorMaxExportBatchSize
+	// Maximum batch size
+	// Note: Must be less than or equal to EnvBatchSpanProcessorMaxQueueSize
+	// i.e. 512
+	EnvBatchSpanProcessorMaxExportBatchSize = "OTEL_BSP_MAX_EXPORT_BATCH_SIZE"
+)
+
+// intEnvOr returns an env variable's numeric value if it is exists (and valid) or the default if not
+func intEnvOr(key string, defaultValue int) int {
+	value, ok := os.LookupEnv(key)
+	if !ok {
+		return defaultValue
+	}
+
+	intValue, err := strconv.Atoi(value)
+	if err != nil {
+		global.Info("Got invalid value, number value expected.", key, value)
+		return defaultValue
+	}
+
+	return intValue
+}

sdk/trace/env_test.go

@@ -0,0 +1,60 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	ottest "go.opentelemetry.io/otel/internal/internaltest"
+)
+
+func TestIntEnvOr(t *testing.T) {
+	testCases := []struct {
+		name          string
+		envValue      string
+		defaultValue  int
+		expectedValue int
+	}{
+		{
+			name:          "IntEnvOrTest - Basic",
+			envValue:      "2500",
+			defaultValue:  500,
+			expectedValue: 2500,
+		},
+		{
+			name:          "IntEnvOrTest - Invalid Number",
+			envValue:      "localhost",
+			defaultValue:  500,
+			expectedValue: 500,
+		},
+	}
+
+	envStore := ottest.NewEnvStore()
+	envStore.Record(EnvBatchSpanProcessorMaxQueueSize)
+	defer func() {
+		require.NoError(t, envStore.Restore())
+	}()
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			require.NoError(t, os.Setenv(EnvBatchSpanProcessorMaxQueueSize, tc.envValue))
+			actualValue := intEnvOr(EnvBatchSpanProcessorMaxQueueSize, tc.defaultValue)
+			assert.Equal(t, tc.expectedValue, actualValue)
+		})
+	}
+}