[apm] standardize peer tag aggregation

comp/trace/config/setup.go

@@ -222,6 +222,10 @@ func applyDatadogConfig(c *config.AgentConfig, core corecompcfg.Component) error
 		c.ConnectionLimit = core.GetInt("apm_config.connection_limit")
 	}
 	c.PeerServiceAggregation = core.GetBool("apm_config.peer_service_aggregation")
+	if c.PeerServiceAggregation {
+		log.Warn("`apm_config.peer_service_aggregation` is deprecated, please use `apm_config.peer_tags_aggregation` instead")
+	}
+	c.PeerTagsAggregation = core.GetBool("apm_config.peer_tags_aggregation")
 	c.ComputeStatsBySpanKind = core.GetBool("apm_config.compute_stats_by_span_kind")
 	if core.IsSet("apm_config.peer_tags") {
 		c.PeerTags = core.GetStringSlice("apm_config.peer_tags")

pkg/config/apm.go

@@ -73,6 +73,7 @@ func setupAPM(config Config) {
 	config.BindEnvAndSetDefault("apm_config.windows_pipe_security_descriptor", "D:AI(A;;GA;;;WD)", "DD_APM_WINDOWS_PIPE_SECURITY_DESCRIPTOR") //nolint:errcheck
 	config.BindEnvAndSetDefault("apm_config.remote_tagger", true, "DD_APM_REMOTE_TAGGER")                                                     //nolint:errcheck
 	config.BindEnvAndSetDefault("apm_config.peer_service_aggregation", false, "DD_APM_PEER_SERVICE_AGGREGATION")                              //nolint:errcheck
+	config.BindEnvAndSetDefault("apm_config.peer_tags_aggregation", false, "DD_APM_PEER_TAGS_AGGREGATION")                                    //nolint:errcheck
 	config.BindEnvAndSetDefault("apm_config.compute_stats_by_span_kind", false, "DD_APM_COMPUTE_STATS_BY_SPAN_KIND")                          //nolint:errcheck
 	config.BindEnvAndSetDefault("apm_config.instrumentation.enabled", false, "DD_APM_INSTRUMENTATION_ENABLED")
 	config.BindEnvAndSetDefault("apm_config.instrumentation.enabled_namespaces", []string{}, "DD_APM_INSTRUMENTATION_ENABLED_NAMESPACES")

pkg/config/config_template.yaml

@@ -1502,19 +1502,26 @@ api_key:
 
   ## @param peer_service_aggregation - bool - default: false
   ## @env DD_APM_PEER_SERVICE_AGGREGATION - bool - default: false
-  ## [BETA] Enables `peer.service` aggregation in the agent. If disabled, aggregated trace stats will not include `peer.service` as a dimension.
-  ## For the best experience with `peer.service`, it is recommended to also enable `compute_stats_by_span_kind`.
-  ## If enabling both causes the Agent to consume too many resources, try disabling `compute_stats_by_span_kind` first.
-  ## If the overhead remains high, it will be due to a high cardinality of `peer.service` values from the traces. You may need to check your instrumentation.
-  ## NOTE: If you are using an OTel tracer it's best to have both enabled because client/producer spans with a `peer.service` value
-  ## may not be marked by the Agent as top-level spans.
+  ## DEPRECATED - please use `peer_tags_aggregation` instead.
   # peer_service_aggregation: false
 
+  ## @param peer_tags_aggregation - bool - default: false
+  ## @env DD_APM_PEER_TAGS_AGGREGATION - bool - default: false
+  ## [BETA] Enables aggregation of peer related tags (e.g., `peer.service`, `db.instance`, etc.) in the Agent.
+  ## If disabled, aggregated trace stats will not include these tags as dimensions on trace metrics.
+  ## For the best experience with peer tags, Datadog also recommends enabling `compute_stats_by_span_kind`.
+  ## If you are using an OTel tracer, it's best to have both enabled because client/producer spans with relevant peer tags
+  ## may not be marked by the Agent as top-level spans.
+  ## If enabling both causes the Agent to consume too many resources, try disabling `compute_stats_by_span_kind` first.
+  ## A high cardinality of peer tags or APM resources can also contribute to higher CPU and memory consumption.
+  ## You can check for the cardinality of these fields by making trace search queries in the Datadog UI.
+  ## The default list of peer tags can be found in pkg/trace/stats/concentrator.go.
+  # peer_tags_aggregation: false
+
   ## @param peer_tags - list of strings - optional
   ## @env DD_APM_PEER_TAGS - list of strings - optional
-  ## [BETA] Enables additional tags related to peer.service. Will not be used unless peer_service_aggregation is also set.
-  ## NOTE: This option is recommended to get the most granular tagging alongside `peer.service`, but it will
-  ## also increase the computational overhead of aggregation. This list can be omitted if that cost is too high for your agent.
+  ## [BETA] Optional list of supplementary peer tags that go beyond the defaults. The Datadog backend validates all tags
+  ## and will drop ones that are unapproved.
   # peer_tags: []
 
   ## @param features - list of strings - optional

pkg/config/config_test.go

@@ -859,6 +859,26 @@ apm_config:
 	require.False(t, testConfig.GetBool("apm_config.peer_service_aggregation"))
 }
 
+func TestEnablePeerTagsAggregationYAML(t *testing.T) {
+	datadogYaml := `
+apm_config:
+  peer_tags_aggregation: true
+`
+	testConfig := SetupConfFromYAML(datadogYaml)
+	err := setupFipsEndpoints(testConfig)
+	require.NoError(t, err)
+	require.True(t, testConfig.GetBool("apm_config.peer_tags_aggregation"))
+
+	datadogYaml = `
+apm_config:
+  peer_tags_aggregation: false
+`
+	testConfig = SetupConfFromYAML(datadogYaml)
+	err = setupFipsEndpoints(testConfig)
+	require.NoError(t, err)
+	require.False(t, testConfig.GetBool("apm_config.peer_tags_aggregation"))
+}
+
 func TestEnablePeerServiceStatsAggregationEnv(t *testing.T) {
 	t.Setenv("DD_APM_PEER_SERVICE_AGGREGATION", "true")
 	testConfig := SetupConfFromYAML("")
@@ -868,6 +888,15 @@ func TestEnablePeerServiceStatsAggregationEnv(t *testing.T) {
 	require.False(t, testConfig.GetBool("apm_config.peer_service_aggregation"))
 }
 
+func TestEnablePeerTagsAggregationEnv(t *testing.T) {
+	t.Setenv("DD_APM_PEER_TAGS_AGGREGATION", "true")
+	testConfig := SetupConfFromYAML("")
+	require.True(t, testConfig.GetBool("apm_config.peer_tags_aggregation"))
+	t.Setenv("DD_APM_PEER_TAGS_AGGREGATION", "false")
+	testConfig = SetupConfFromYAML("")
+	require.False(t, testConfig.GetBool("apm_config.peer_tags_aggregation"))
+}
+
 func TestEnableStatsComputationBySpanKindYAML(t *testing.T) {
 	datadogYaml := `
 apm_config:

pkg/flare/envvars.go

@@ -71,6 +71,7 @@ var allowedEnvvarNames = []string{
 	"DD_APM_REMOTE_TAGGER",
 	"DD_APM_PEER_SERVICE_AGGREGATION",
 	"DD_APM_COMPUTE_STATS_BY_SPAN_KIND",
+	"DD_APM_PEER_TAGS_AGGREGATION",
 	"DD_APM_PEER_TAGS",
 	"DD_APM_MAX_CATALOG_SERVICES",
 	"DD_APM_RECEIVER_TIMEOUT",

pkg/proto/datadog/trace/stats.proto

@@ -14,6 +14,9 @@ message StatsPayload {
 	repeated ClientStatsPayload stats = 3;
 	string agentVersion = 4;
 	bool clientComputed = 5;
+	// splitPayload indicates if the payload is actually one of several payloads split out from a larger payload.
+	// This field can be used in the backend to signal if re-aggregation is necessary.
+	bool splitPayload = 6;
 }
 
 // ClientStatsPayload is the first layer of span stats aggregation. It is also
@@ -70,9 +73,9 @@ message ClientGroupedStats {
 	bytes errorSummary = 11; // ddsketch summary of error spans latencies encoded in protobuf
 	bool synthetics = 12; // set to true on spans generated by synthetics traffic
 	uint64 topLevelHits = 13; // count of top level spans aggregated in the groupedstats
-	string peer_service = 14; // name of the remote service that the `service` communicated with
+	reserved 14; // peer_service has been deprecated
 	string span_kind = 15; // value of the span.kind tag on the span
-	// peer_tags are supplementary tags that further describe a peer_service
-	// E.g., `aws.s3.bucket` gives a specific bucket for `peer_service = aws-s3`
+	// peer_tags are supplementary tags that further describe a peer entity
+	// E.g., `grpc.target` to describe the name of a gRPC peer, or `db.hostname` to describe the name of peer DB
 	repeated string peer_tags = 16;
 }