Custom Events Limiter (#524)

Allows custom events to be configured by users and adds tests to verify changes.

v3/internal/connect_reply.go

@@ -137,20 +137,20 @@ func (r *ConnectReply) ConfigurablePeriod() time.Duration {
 func uintPtr(x uint) *uint { return &x }
 
 // DefaultEventHarvestConfig provides faster event harvest defaults.
-func DefaultEventHarvestConfig(maxTxnEvents, maxLogEvents int) EventHarvestConfig {
+func DefaultEventHarvestConfig(maxTxnEvents, maxLogEvents, maxCustomEvents int) EventHarvestConfig {
 	cfg := EventHarvestConfig{}
 	cfg.ReportPeriodMs = DefaultConfigurableEventHarvestMs
 	cfg.Limits.TxnEvents = uintPtr(uint(maxTxnEvents))
-	cfg.Limits.CustomEvents = uintPtr(uint(MaxCustomEvents))
+	cfg.Limits.CustomEvents = uintPtr(uint(maxCustomEvents))
 	cfg.Limits.LogEvents = uintPtr(uint(maxLogEvents))
 	cfg.Limits.ErrorEvents = uintPtr(uint(MaxErrorEvents))
 	return cfg
 }
 
 // DefaultEventHarvestConfigWithDT is an extended version of DefaultEventHarvestConfig,
 // with the addition that it takes into account distributed tracer span event harvest limits.
-func DefaultEventHarvestConfigWithDT(maxTxnEvents, maxLogEvents, spanEventLimit int, dtEnabled bool) EventHarvestConfig {
-	cfg := DefaultEventHarvestConfig(maxTxnEvents, maxLogEvents)
+func DefaultEventHarvestConfigWithDT(maxTxnEvents, maxLogEvents, maxCustomEvents, spanEventLimit int, dtEnabled bool) EventHarvestConfig {
+	cfg := DefaultEventHarvestConfig(maxTxnEvents, maxLogEvents, maxCustomEvents)
 	if dtEnabled {
 		cfg.Limits.SpanEvents = uintPtr(uint(spanEventLimit))
 	}

v3/internal/connect_reply_test.go

@@ -173,7 +173,7 @@ func TestNegativeHarvestLimits(t *testing.T) {
 }
 
 func TestDefaultEventHarvestConfigJSON(t *testing.T) {
-	js, err := json.Marshal(DefaultEventHarvestConfig(MaxTxnEvents, MaxLogEvents))
+	js, err := json.Marshal(DefaultEventHarvestConfig(MaxTxnEvents, MaxLogEvents, MaxCustomEvents))
 	if err != nil {
 		t.Error(err)
 	}

v3/newrelic/config.go

@@ -71,6 +71,8 @@ type Config struct {
 		// custom analytics events.  High security mode overrides this
 		// setting.
 		Enabled bool
+		// MaxSamplesStored sets the desired maximum custom event samples stored
+		MaxSamplesStored int
 	}
 
 	// TransactionEvents controls the behavior of transaction analytics
@@ -408,6 +410,7 @@ func defaultConfig() Config {
 	c.Enabled = true
 	c.Labels = make(map[string]string)
 	c.CustomInsightsEvents.Enabled = true
+	c.CustomInsightsEvents.MaxSamplesStored = internal.MaxCustomEvents
 	c.TransactionEvents.Enabled = true
 	c.TransactionEvents.Attributes.Enabled = true
 	c.TransactionEvents.MaxSamplesStored = internal.MaxTxnEvents
@@ -545,12 +548,22 @@ func (c Config) maxTxnEvents() int {
 	return configured
 }
 
-// maxTxnEvents returns the configured maximum number of Transaction Events if it has been configured
+// maxCustomEvents returns the configured maximum number of Custom Events if it has been configured
+// and is less than the default maximum; otherwise it returns the default max.
+func (c Config) maxCustomEvents() int {
+	configured := c.CustomInsightsEvents.MaxSamplesStored
+	if configured < 0 || configured > internal.MaxCustomEvents {
+		return internal.MaxCustomEvents
+	}
+	return configured
+}
+
+// maxLogEvents returns the configured maximum number of Log Events if it has been configured
 // and is less than the default maximum; otherwise it returns the default max.
 func (c Config) maxLogEvents() int {
 	configured := c.ApplicationLogging.Forwarding.MaxSamplesStored
-	if configured < 0 || configured > internal.MaxTxnEvents {
-		return internal.MaxTxnEvents
+	if configured < 0 || configured > internal.MaxLogEvents {
+		return internal.MaxLogEvents
 	}
 	return configured
 }
@@ -709,7 +722,7 @@ func configConnectJSONInternal(c Config, pid int, util *utilization.Data, e envi
 		Util:             util,
 		SecurityPolicies: securityPolicies,
 		Metadata:         metadata,
-		EventData:        internal.DefaultEventHarvestConfigWithDT(c.maxTxnEvents(), c.maxLogEvents(), c.DistributedTracer.ReservoirLimit, c.DistributedTracer.Enabled),
+		EventData:        internal.DefaultEventHarvestConfigWithDT(c.maxTxnEvents(), c.maxLogEvents(), c.maxCustomEvents(), c.DistributedTracer.ReservoirLimit, c.DistributedTracer.Enabled),
 	}})
 }
 

v3/newrelic/config_options.go

@@ -36,6 +36,13 @@ func ConfigDistributedTracerEnabled(enabled bool) ConfigOption {
 	return func(cfg *Config) { cfg.DistributedTracer.Enabled = enabled }
 }
 
+// ConfigCustomInsightsEventsMaxSamplesStored alters the sample size allowing control
+// of how many custom events are stored in an agent for a given harvest cycle.
+// Alters the CustomInsightsEvents.MaxSamplesStored setting.
+func ConfigCustomInsightsEventsMaxSamplesStored(limit int) ConfigOption {
+	return func(cfg *Config) { cfg.CustomInsightsEvents.MaxSamplesStored = limit }
+}
+
 // ConfigDistributedTracerReservoirLimit alters the sample reservoir size (maximum
 // number of span events to be collected) for distributed tracing instead of
 // using the built-in default.

v3/newrelic/config_test.go

@@ -145,7 +145,10 @@ func TestCopyConfigReferenceFieldsPresent(t *testing.T) {
 				"Enabled":true
 			},
 			"CrossApplicationTracer":{"Enabled":false},
-			"CustomInsightsEvents":{"Enabled":true},
+			"CustomInsightsEvents":{
+				"Enabled":true,
+				"MaxSamplesStored":10000
+			},
 			"DatastoreTracer":{
 				"DatabaseNameReporting":{"Enabled":true},
 				"InstanceReporting":{"Enabled":true},
@@ -333,7 +336,10 @@ func TestCopyConfigReferenceFieldsAbsent(t *testing.T) {
 				"Enabled":true
 			},
 			"CrossApplicationTracer":{"Enabled":false},
-			"CustomInsightsEvents":{"Enabled":true},
+			"CustomInsightsEvents":{
+				"Enabled":true,
+				"MaxSamplesStored":10000
+			},
 			"DatastoreTracer":{
 				"DatabaseNameReporting":{"Enabled":true},
 				"InstanceReporting":{"Enabled":true},
@@ -797,3 +803,13 @@ func TestNewInternalConfig(t *testing.T) {
 		t.Error(c.metadata)
 	}
 }
+
+func TestConfigurableMaxCustomEvents(t *testing.T) {
+	expected := 1000
+	cfg := config{Config: defaultConfig()}
+	cfg.CustomInsightsEvents.MaxSamplesStored = expected
+	result := cfg.maxCustomEvents()
+	if result != expected {
+		t.Errorf("Unexpected max number of custom events, expected %d but got %d", expected, result)
+	}
+}