Fix rate limiting sampler to drop trace when lower bound is zero (#3604)

* Fix rate limiting sampler to drop trace when lower bound is zero

* Add change log entry

* Update CHANGELOG.md

Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

---------

Co-authored-by: Chester Cheung <cheung.zhy.csu@gmail.com>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

CHANGELOG.md

@@ -15,7 +15,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ### Fixed
 
-- - AWS SDK span name to be of the format `Service.Operation` in `go.opentelemetry.io/contrib/instrumentation/github.com/aws/aws-sdk-go-v2/otelaws`. (#3582, #3521)
+- AWS SDK span name to be of the format `Service.Operation` in `go.opentelemetry.io/contrib/instrumentation/github.com/aws/aws-sdk-go-v2/otelaws`. (#3582, #3521)
+- Prevent sampler configuration reset from erroneously sampling first span in `go.opentelemetry.io/contrib/samplers/jaegerremote`. (#3603, #3604)
 
 ## [1.16.0-rc.1/0.41.0-rc.1/0.9.0-rc.1] - 2023-03-02
 

samplers/jaegerremote/internal/utils/rate_limiter.go

@@ -49,9 +49,14 @@ type RateLimiter struct {
 
 // NewRateLimiter creates a new RateLimiter.
 func NewRateLimiter(creditsPerSecond, maxBalance float64) *RateLimiter {
+	balance := maxBalance
+	if creditsPerSecond == 0 {
+		balance = 0
+	}
+
 	return &RateLimiter{
 		creditsPerSecond: creditsPerSecond,
-		balance:          maxBalance,
+		balance:          balance,
 		maxBalance:       maxBalance,
 		lastTick:         time.Now(),
 		timeNow:          time.Now,

samplers/jaegerremote/sampler_test.go

@@ -71,6 +71,10 @@ func TestRateLimitingSampler(t *testing.T) {
 	assert.Equal(t, trace.RecordAndSample, result.Decision)
 	result = sampler.ShouldSample(trace.SamplingParameters{Name: testOperationName})
 	assert.Equal(t, trace.Drop, result.Decision)
+
+	sampler = newRateLimitingSampler(0)
+	result = sampler.ShouldSample(trace.SamplingParameters{Name: testOperationName})
+	assert.Equal(t, trace.Drop, result.Decision)
 }
 
 func TestGuaranteedThroughputProbabilisticSamplerUpdate(t *testing.T) {