Cleanup UID/InstanceID duplicity. Also remove override_instance_id …

…config option (#1125)

* Cleanup UID/InstanceID duplicity

* rm override_instance_id from documentation

docs/sources/configure/options.md

@@ -604,14 +604,6 @@ instead of trying to automatically resolve the host name.
 
 This option takes precedence over `dns`.
 
-| YAML                   | Environment variable             | Type   | Default |
-| ---------------------- | ------------------- | ------ | ------- |
-| `override_instance_id` | `BEYLA_INSTANCE_ID` | string | (unset) |
-
-If set, Beyla will use this value directly as instance ID of any instrumented
-process. If you are managing multiple processes from a single Beyla instance,
-all the processes will have the same instance ID.
-
 ### Kubernetes decorator
 
 If you run Beyla in a Kubernetes environment, you can configure it to decorate the traces

pkg/export/otel/common.go

@@ -62,7 +62,7 @@ var DefaultBuckets = Buckets{
 
 func getAppResourceAttrs(hostID string, service *svc.ID) []attribute.KeyValue {
 	return append(getResourceAttrs(hostID, service),
-		semconv.ServiceInstanceID(service.Instance),
+		semconv.ServiceInstanceID(string(service.UID)),
 	)
 }
 

pkg/export/otel/metrics.go

@@ -710,7 +710,7 @@ func otelHistogramConfig(metricName string, buckets []float64, useExponentialHis
 func (mr *MetricsReporter) metricResourceAttributes(service *svc.ID) attribute.Set {
 	attrs := []attribute.KeyValue{
 		request.ServiceMetric(service.Name),
-		semconv.ServiceInstanceID(service.Instance),
+		semconv.ServiceInstanceID(string(service.UID)),
 		semconv.ServiceNamespace(service.Namespace),
 		semconv.TelemetrySDKLanguageKey.String(service.SDKLanguage.String()),
 		semconv.TelemetrySDKNameKey.String("beyla"),

pkg/export/prom/prom.go

@@ -711,7 +711,7 @@ func (r *metricsReporter) labelValuesSpans(span *request.Span) []string {
 		span.TraceName(),
 		strconv.Itoa(int(request.SpanStatusCode(span))),
 		span.ServiceGraphKind(),
-		span.ServiceID.Instance,
+		string(span.ServiceID.UID), // app instance ID
 		job,
 		"beyla",
 	}
@@ -737,7 +737,7 @@ func (r *metricsReporter) labelValuesTargetInfo(service svc.ID) []string {
 		service.HostName,
 		service.Name,
 		service.Namespace,
-		service.Instance,
+		string(service.UID), // app instance ID
 		job,
 		service.SDKLanguage.String(),
 		"beyla",

pkg/internal/request/span_getters.go

@@ -57,8 +57,6 @@ func SpanOTELGetters(name attr.Name) (attributes.Getter[*Span, attribute.KeyValu
 		}
 	case attr.Service:
 		getter = func(s *Span) attribute.KeyValue { return ServiceMetric(s.ServiceID.Name) }
-	case attr.ServiceInstanceID:
-		getter = func(s *Span) attribute.KeyValue { return semconv.ServiceInstanceID(s.ServiceID.Instance) }
 	case attr.ServiceName:
 		getter = func(s *Span) attribute.KeyValue { return semconv.ServiceName(s.ServiceID.Name) }
 	case attr.ServiceNamespace:

pkg/internal/svc/svc.go

@@ -59,10 +59,8 @@ const (
 // ID stores the metadata attributes of a service/resource
 // TODO: rename to svc.Attributes
 type ID struct {
-	// UID might coincide with other fields (usually, Instance), but UID
-	// can't be overriden by the user, so it's the only field that can be
-	// used for internal differentiation of the users.
-	// UID is not exported in the metrics or traces.
+	// UID uniquely identifies a service instance. It is not exported
+	// in the metrics or traces, but it is used to compose the InstanceID
 	UID UID
 
 	Name string
@@ -71,7 +69,6 @@ type ID struct {
 	// again with Kubernetes metadata).
 	Namespace   string
 	SDKLanguage InstrumentableType
-	Instance    string
 
 	Metadata map[attr.Name]string
 

pkg/internal/traces/read_decorator.go

@@ -29,10 +29,6 @@ type InstanceIDConfig struct {
 	// value. Beyla will anyway attach the process ID to the given hostname for composing
 	// the instance ID.
 	OverrideHostname string `yaml:"override_hostname" env:"BEYLA_HOSTNAME"`
-	// OverrideInstanceID can be optionally set to avoid Beyla composing the instance ID
-	// and use this value. If you are managing multiple processes from a single Beyla instance,
-	// all the processes will have the same Instance ID.
-	OverrideInstanceID string `yaml:"override_instance_id" env:"BEYLA_INSTANCE_ID"`
 
 	// Undocumented properties aimed at fine-grained tuning
 
@@ -55,7 +51,7 @@ type ReadDecorator struct {
 type decorator func(spans []request.Span)
 
 func ReadFromChannel(ctx context.Context, r *ReadDecorator) pipe.StartFunc[[]request.Span] {
-	decorate := getDecorator(&r.InstanceID)
+	decorate := hostNamePIDDecorator(&r.InstanceID)
 	return func(out chan<- []request.Span) {
 		cancelChan := ctx.Done()
 		for {
@@ -76,30 +72,14 @@ func ReadFromChannel(ctx context.Context, r *ReadDecorator) pipe.StartFunc[[]req
 	}
 }
 
-func getDecorator(cfg *InstanceIDConfig) decorator {
-	hnPidDecorator := hostNamePIDDecorator(cfg)
-	if cfg.OverrideInstanceID == "" {
-		return hnPidDecorator
-	}
-	return func(spans []request.Span) {
-		// first decorate normally
-		hnPidDecorator(spans)
-		// later, override instance IDs
-		for i := range spans {
-			spans[i].ServiceID.Instance = cfg.OverrideInstanceID
-		}
-	}
-}
-
 func hostNamePIDDecorator(cfg *InstanceIDConfig) decorator {
 	// TODO: periodically update in case the current Beyla instance is created from a VM snapshot running as a different hostname
 	resolver := hostname.CreateResolver(cfg.OverrideHostname, "", cfg.HostnameDNSResolution)
 	fullHostName, _, err := resolver.Query()
 	log := rlog().With("function", "instance_ID_hostNamePIDDecorator")
 	if err != nil {
 		log.Warn("can't read hostname. Leaving empty. Consider overriding"+
-			" the BEYLA_HOSTNAME or BEYLA_INSTANCE_ID properties",
-			"error", err)
+			" the BEYLA_HOSTNAME property", "error", err)
 	} else {
 		log.Info("using hostname", "hostname", fullHostName)
 	}
@@ -109,17 +89,16 @@ func hostNamePIDDecorator(cfg *InstanceIDConfig) decorator {
 	if cfg.InternalIDCacheLen != 0 {
 		cacheLen = cfg.InternalIDCacheLen
 	}
-	idsCache, _ := lru.New[uint32, string](cacheLen)
+	uidsCache, _ := lru.New[uint32, svc.UID](cacheLen)
 
 	return func(spans []request.Span) {
 		for i := range spans {
-			instanceID, ok := idsCache.Get(spans[i].Pid.HostPID)
+			uid, ok := uidsCache.Get(spans[i].Pid.HostPID)
 			if !ok {
-				instanceID = fullHostName + "-" + strconv.Itoa(int(spans[i].Pid.HostPID))
-				idsCache.Add(spans[i].Pid.HostPID, instanceID)
+				uid = svc.UID(fullHostName + "-" + strconv.Itoa(int(spans[i].Pid.HostPID)))
+				uidsCache.Add(spans[i].Pid.HostPID, uid)
 			}
-			spans[i].ServiceID.Instance = instanceID
-			spans[i].ServiceID.UID = svc.UID(instanceID)
+			spans[i].ServiceID.UID = uid
 			spans[i].ServiceID.HostName = fullHostName
 		}
 	}

pkg/internal/traces/read_decorator_test.go

@@ -27,35 +27,23 @@ func TestReadDecorator(t *testing.T) {
 	type testCase struct {
 		desc        string
 		cfg         ReadDecorator
-		expectedID  string
 		expectedUID svc.UID
 		expectedHN  string
 	}
 	for _, tc := range []testCase{{
 		desc:        "dns",
 		cfg:         ReadDecorator{InstanceID: InstanceIDConfig{HostnameDNSResolution: true}},
-		expectedID:  dnsHostname + "-1234",
 		expectedUID: svc.UID(dnsHostname + "-1234"),
 		expectedHN:  dnsHostname,
 	}, {
 		desc:        "no-dns",
-		expectedID:  localHostname + "-1234",
 		expectedUID: svc.UID(localHostname + "-1234"),
 		expectedHN:  localHostname,
 	}, {
 		desc:        "override hostname",
 		cfg:         ReadDecorator{InstanceID: InstanceIDConfig{OverrideHostname: "foooo"}},
-		expectedID:  "foooo-1234",
 		expectedUID: "foooo-1234",
 		expectedHN:  "foooo",
-	}, {
-		desc:       "override HN",
-		cfg:        ReadDecorator{InstanceID: InstanceIDConfig{OverrideInstanceID: "instanceee"}},
-		expectedID: "instanceee",
-		// even if we override instance ID, the UID should be set to a really unique value
-		// (same as the automatic instanceID value)
-		expectedUID: svc.UID(localHostname + "-1234"),
-		expectedHN:  localHostname,
 	}} {
 		t.Run(tc.desc, func(t *testing.T) {
 			cfg := tc.cfg
@@ -72,9 +60,9 @@ func TestReadDecorator(t *testing.T) {
 			}
 			outSpans := testutil.ReadChannel(t, decoratedOutput, testTimeout)
 			assert.Equal(t, []request.Span{
-				{ServiceID: svc.ID{Instance: tc.expectedID, UID: tc.expectedUID, HostName: tc.expectedHN},
+				{ServiceID: svc.ID{UID: tc.expectedUID, HostName: tc.expectedHN},
 					Path: "/foo", Pid: request.PidInfo{HostPID: 1234}},
-				{ServiceID: svc.ID{Instance: tc.expectedID, UID: tc.expectedUID, HostName: tc.expectedHN},
+				{ServiceID: svc.ID{UID: tc.expectedUID, HostName: tc.expectedHN},
 					Path: "/bar", Pid: request.PidInfo{HostPID: 1234}},
 			}, outSpans)
 		})

pkg/transform/k8s.go

@@ -112,6 +112,10 @@ func (md *metadataDecorator) appendMetadata(span *request.Span, info *kube.PodIn
 	if span.ServiceID.Namespace == "" {
 		span.ServiceID.Namespace = info.Namespace
 	}
+	// overriding the UID here will avoid reusing the OTEL resource reporter
+	// if the application/process was discovered and reported information
+	// before the kubernetes metadata was available
+	// (related issue: /~https://github.com/grafana/beyla/issues/1124)
 	span.ServiceID.UID = svc.UID(info.UID)
 
 	// if, in the future, other pipeline steps modify the service metadata, we should