Merge branch 'main' into mymain

.github/dependabot.yml

@@ -586,6 +586,15 @@ updates:
     schedule:
       interval: weekly
       day: sunday
+  - package-ecosystem: gomod
+    directory: /samplers/aws/xray
+    labels:
+      - dependencies
+      - go
+      - Skip Changelog
+    schedule:
+      interval: weekly
+      day: sunday
   - package-ecosystem: gomod
     directory: /samplers/jaegerremote
     labels:

samplers/aws/xray/fallback_sampler.go

@@ -0,0 +1,102 @@
+// 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 xray // import "go.opentelemetry.io/contrib/samplers/aws/xray"
+
+import (
+	"sync"
+	"time"
+
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// FallbackSampler does the sampling at a rate of 1 req/sec and 5% of additional requests.
+type FallbackSampler struct {
+	lastTick       time.Time
+	quotaBalance   float64
+	defaultSampler sdktrace.Sampler
+	mu             sync.RWMutex
+}
+
+// Compile time assertion that remoteSampler implements the Sampler interface.
+var _ sdktrace.Sampler = (*FallbackSampler)(nil)
+
+// NewFallbackSampler returns a FallbackSampler which samples 1 req/sec and additional 5% of requests using traceIDRatioBasedSampler.
+func NewFallbackSampler() *FallbackSampler {
+	return &FallbackSampler{
+		defaultSampler: sdktrace.TraceIDRatioBased(0.05),
+		quotaBalance:   1.0,
+	}
+}
+
+// ShouldSample implements the logic of borrowing 1 req/sec and then use traceIDRatioBasedSampler to sample 5% of additional requests.
+func (fs *FallbackSampler) ShouldSample(parameters sdktrace.SamplingParameters) sdktrace.SamplingResult {
+	// borrowing one request every second
+	if fs.take(time.Now(), 1.0) {
+		return sdktrace.SamplingResult{
+			Tracestate: trace.SpanContextFromContext(parameters.ParentContext).TraceState(),
+			Decision:   sdktrace.RecordAndSample,
+		}
+	}
+
+	// traceIDRatioBasedSampler to sample 5% of additional requests every second
+	return fs.defaultSampler.ShouldSample(parameters)
+}
+
+// Description returns description of the sampler being used.
+func (fs *FallbackSampler) Description() string {
+	return "FallbackSampler{fallback sampling with sampling config of 1 req/sec and 5% of additional requests}"
+}
+
+// take consumes quota from reservoir, if any remains, then returns true. False otherwise.
+func (fs *FallbackSampler) take(now time.Time, itemCost float64) bool {
+	fs.mu.Lock()
+	defer fs.mu.Unlock()
+
+	if fs.lastTick.IsZero() {
+		fs.lastTick = now
+	}
+
+	if fs.quotaBalance >= itemCost {
+		fs.quotaBalance -= itemCost
+		return true
+	}
+
+	// update quota balance based on elapsed time
+	fs.refreshQuotaBalanceLocked(now)
+
+	if fs.quotaBalance >= itemCost {
+		fs.quotaBalance -= itemCost
+		return true
+	}
+
+	return false
+}
+
+// refreshQuotaBalanceLocked refreshes the quotaBalance considering elapsedTime.
+// It is assumed the lock is held when calling this.
+func (fs *FallbackSampler) refreshQuotaBalanceLocked(now time.Time) {
+	elapsedTime := now.Sub(fs.lastTick)
+	fs.lastTick = now
+
+	// when elapsedTime is higher than 1 even then we need to keep quotaBalance
+	// near to 1 so making elapsedTime to 1 for only borrowing 1 per second case
+	if elapsedTime.Seconds() > 1.0 {
+		fs.quotaBalance += 1.0
+	} else {
+		// calculate how much credit have we accumulated since the last tick
+		fs.quotaBalance += elapsedTime.Seconds()
+	}
+}

samplers/aws/xray/fallback_sampler_test.go

@@ -0,0 +1,74 @@
+// 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 xray
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+
+	"go.opentelemetry.io/otel/sdk/trace"
+)
+
+// assert sampling using fallback sampler.
+func TestSampleUsingFallbackSampler(t *testing.T) {
+	fs := NewFallbackSampler()
+	assert.NotEmpty(t, fs.defaultSampler)
+	assert.Equal(t, fs.quotaBalance, 1.0)
+
+	sd := fs.ShouldSample(trace.SamplingParameters{})
+	assert.Equal(t, trace.RecordAndSample, sd.Decision)
+}
+
+// assert that we only borrow 1 req/sec.
+func TestBorrowOnePerSecond(t *testing.T) {
+	fs := NewFallbackSampler()
+	borrowed := fs.take(time.Unix(1500000000, 0), 1.0)
+
+	// assert that borrowing one per second
+	assert.True(t, borrowed)
+
+	borrowed = fs.take(time.Unix(1500000000, 0), 1.0)
+
+	// assert that borrowing again is false during that second
+	assert.False(t, borrowed)
+
+	borrowed = fs.take(time.Unix(1500000001, 0), 1.0)
+
+	// assert that borrowing again in next second
+	assert.True(t, borrowed)
+}
+
+// assert that when elapsedTime is high quotaBalance should still be close to 1.
+func TestBorrowWithLargeElapsedTime(t *testing.T) {
+	fs := NewFallbackSampler()
+	borrowed := fs.take(time.Unix(1500000000, 0), 1.0)
+
+	// assert that borrowing one per second
+	assert.True(t, borrowed)
+
+	// Increase the time by 9 seconds
+	borrowed = fs.take(time.Unix(1500000009, 0), 1.0)
+	assert.True(t, borrowed)
+	assert.Equal(t, fs.quotaBalance, 0.0)
+}
+
+// assert fallback sampling description.
+func TestFallbackSamplerDescription(t *testing.T) {
+	fs := NewFallbackSampler()
+	s := fs.Description()
+	assert.Equal(t, s, "FallbackSampler{fallback sampling with sampling config of 1 req/sec and 5% of additional requests}")
+}

samplers/aws/xray/go.mod

@@ -0,0 +1,13 @@
+module go.opentelemetry.io/contrib/samplers/aws/xray
+
+go 1.16
+
+require (
+	github.com/go-logr/logr v1.2.3
+	github.com/go-logr/stdr v1.2.2
+	github.com/stretchr/testify v1.7.1
+	go.opentelemetry.io/otel v1.6.0
+	go.opentelemetry.io/otel/sdk v1.6.0
+	go.opentelemetry.io/otel/trace v1.6.0
+	golang.org/x/sys v0.0.0-20210510120138-977fb7262007 // indirect
+)

samplers/aws/xray/go.sum

@@ -0,0 +1,28 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
+github.com/go-logr/logr v1.2.3/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/google/go-cmp v0.5.7 h1:81/ik6ipDQS2aGcBfIN5dHDB36BwrStyeAQquSYCV4o=
+github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+go.opentelemetry.io/otel v1.6.0 h1:YV6GkGe/Ag2PKsm4rjlqdSNs0w0A5ZzxeGkxhx1T+t4=
+go.opentelemetry.io/otel v1.6.0/go.mod h1:bfJD2DZVw0LBxghOTlgnlI0CV3hLDu9XF/QKOUXMTQQ=
+go.opentelemetry.io/otel/sdk v1.6.0 h1:JoriAoiNENuxxIQApR1O0k2h1Md5QegZhbentcRJpWk=
+go.opentelemetry.io/otel/sdk v1.6.0/go.mod h1:PjLRUfDsoPy0zl7yrDGSUqjj43tL7rEtFdCEiGlxXRM=
+go.opentelemetry.io/otel/trace v1.6.0 h1:NDzPermp9ISkhxIaJXjBTi2O60xOSHDHP/EezjOL2wo=
+go.opentelemetry.io/otel/trace v1.6.0/go.mod h1:qs7BrU5cZ8dXQHBGxHMOxwME/27YH2qEp4/+tZLLwJE=
+golang.org/x/sys v0.0.0-20210423185535-09eb48e85fd7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007 h1:gG67DSER+11cZvqIMb8S8bt0vZtiN6xWYARwirrOSfE=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=