Fix for jaegertracing#5270 - return default probabilistic operation l…

…evel strategies for ratelimiting service configurations

Signed-off-by: Kazimieras Pociunas <[email protected]>

plugin/sampling/strategystore/static/strategy_store.go

@@ -229,13 +229,16 @@ func (h *strategyStore) parseStrategies(strategies *strategies) {
 		// is not merged with and only used as a fallback).
 		opS := newStore.serviceStrategies[s.Service].OperationSampling
 		if opS == nil {
-			if newStore.defaultStrategy.OperationSampling == nil ||
-				newStore.serviceStrategies[s.Service].ProbabilisticSampling == nil {
+			// no default per-operation strategies - just move on
+			if newStore.defaultStrategy.OperationSampling == nil {
 				continue
 			}
-			// Service has no per-operation strategies, so just reference the default settings and change default samplingRate.
+			// Service has no per-operation strategies, so just reference the default settings
+			// and change default samplingRate to the value defined in service strategy if value is available.
 			newOpS := *newStore.defaultStrategy.OperationSampling
-			newOpS.DefaultSamplingProbability = newStore.serviceStrategies[s.Service].ProbabilisticSampling.SamplingRate
+			if newStore.serviceStrategies[s.Service].ProbabilisticSampling != nil {
+				newOpS.DefaultSamplingProbability = newStore.serviceStrategies[s.Service].ProbabilisticSampling.SamplingRate
+			}
 			newStore.serviceStrategies[s.Service].OperationSampling = &newOpS
 			continue
 		}

plugin/sampling/strategystore/static/strategy_store_test.go

@@ -470,12 +470,24 @@ func TestServiceNoPerOperationStrategies(t *testing.T) {
 
 	s, err := store.GetSamplingStrategy(context.Background(), "ServiceA")
 	require.NoError(t, err)
-	assert.Equal(t, 1.0, s.OperationSampling.DefaultSamplingProbability)
+	require.NotNil(t, s.OperationSampling)
+	os := s.OperationSampling
+	assert.EqualValues(t, 1, os.DefaultSamplingProbability)
+	require.Len(t, os.PerOperationStrategies, 1)
+	assert.Equal(t, "/health", os.PerOperationStrategies[0].Operation)
+	assert.EqualValues(t, 0.0, os.PerOperationStrategies[0].ProbabilisticSampling.SamplingRate)
+	expected := makeResponse(api_v2.SamplingStrategyType_PROBABILISTIC, 1.0)
+	assert.Equal(t, *expected.ProbabilisticSampling, *s.ProbabilisticSampling)
 
 	s, err = store.GetSamplingStrategy(context.Background(), "ServiceB")
 	require.NoError(t, err)
-
-	expected := makeResponse(api_v2.SamplingStrategyType_RATE_LIMITING, 3)
+	require.NotNil(t, s.OperationSampling)
+	os = s.OperationSampling
+	assert.EqualValues(t, 0.2, os.DefaultSamplingProbability)
+	require.Len(t, os.PerOperationStrategies, 1)
+	assert.Equal(t, "/health", os.PerOperationStrategies[0].Operation)
+	assert.EqualValues(t, 0.0, os.PerOperationStrategies[0].ProbabilisticSampling.SamplingRate)
+	expected = makeResponse(api_v2.SamplingStrategyType_RATE_LIMITING, 3)
 	assert.Equal(t, *expected.RateLimitingSampling, *s.RateLimitingSampling)
 }