feature: recover ratelimiter first pass strategy

CHANGELOG.md

@@ -9,7 +9,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ## [Unreleased]
 
 ### Fixed
-- Fixed jaegerremote sampler not behaving properly with per operation startegy set. (#2137)
+- Fixed jaegerremote sampler not behaving properly with per operation strategy set. (#2137)
 
 ## [1.6.0/0.31.0] - 2022-03-28
 

samplers/jaegerremote/internal/utils/rate_limiter.go

@@ -17,7 +17,6 @@
 package utils // import "go.opentelemetry.io/contrib/samplers/jaegerremote/internal/utils"
 
 import (
-	"math"
 	"sync"
 	"time"
 )
@@ -53,7 +52,7 @@ type RateLimiter struct {
 func NewRateLimiter(creditsPerSecond, maxBalance float64) *RateLimiter {
 	return &RateLimiter{
 		creditsPerSecond: creditsPerSecond,
-		balance:          math.Min(creditsPerSecond, maxBalance),
+		balance:          maxBalance,
 		maxBalance:       maxBalance,
 		lastTick:         time.Now(),
 		timeNow:          time.Now,

samplers/jaegerremote/sampler_remote_test.go

@@ -271,7 +271,11 @@ func TestRemotelyControlledSampler_updateSampler(t *testing.T) {
 			assert.NotEqual(t, initSampler, sampler.sampler, "Sampler should have been updated")
 			assert.Equal(t, test.expectedDefaultProbability, s.defaultSampler.SamplingRate())
 
-			result := sampler.ShouldSample(makeSamplingParameters(testMaxID-10, testOperationName))
+			// First call is always sampled
+			result := sampler.ShouldSample(makeSamplingParameters(testMaxID+10, testOperationName))
+			assert.Equal(t, trace.RecordAndSample, result.Decision)
+
+			result = sampler.ShouldSample(makeSamplingParameters(testMaxID-10, testOperationName))
 			assert.Equal(t, trace.RecordAndSample, result.Decision)
 		})
 	}
@@ -285,6 +289,7 @@ func TestRemotelyControlledSampler_multiStrategyResponse(t *testing.T) {
 
 	defaultSampingRate := 1.0
 	testUnusedOpName := "unused_op"
+	testUnusedOpSamplingRate := 0.0
 
 	res := &jaeger_api_v2.SamplingStrategyResponse{
 		StrategyType:          jaeger_api_v2.SamplingStrategyType_PROBABILISTIC,
@@ -296,7 +301,7 @@ func TestRemotelyControlledSampler_multiStrategyResponse(t *testing.T) {
 				{
 					Operation: testUnusedOpName,
 					ProbabilisticSampling: &jaeger_api_v2.ProbabilisticSamplingStrategy{
-						SamplingRate: 0.0,
+						SamplingRate: testUnusedOpSamplingRate,
 					}},
 			},
 		},
@@ -310,7 +315,10 @@ func TestRemotelyControlledSampler_multiStrategyResponse(t *testing.T) {
 	assert.Equal(t, defaultSampingRate, s.defaultSampler.SamplingRate())
 
 	result := sampler.ShouldSample(makeSamplingParameters(testMaxID-10, testUnusedOpName))
+	assert.Equal(t, trace.RecordAndSample, result.Decision) // first call always pass
+	result = sampler.ShouldSample(makeSamplingParameters(testMaxID, testUnusedOpName))
 	assert.Equal(t, trace.Drop, result.Decision)
+
 }
 
 func TestSamplerQueryError(t *testing.T) {

samplers/jaegerremote/sampler_test.go

@@ -68,6 +68,8 @@ func TestRateLimitingSampler(t *testing.T) {
 
 	sampler = newRateLimitingSampler(0.1)
 	result = sampler.ShouldSample(trace.SamplingParameters{Name: testOperationName})
+	assert.Equal(t, trace.RecordAndSample, result.Decision)
+	result = sampler.ShouldSample(trace.SamplingParameters{Name: testOperationName})
 	assert.Equal(t, trace.Drop, result.Decision)
 }