Add server side apm stats computation (#606)

Author: hghotra

aws/logs_monitoring/tools/integration_tests/snapshots/cloudwatch_log_lambda_invocation.json~snapshot

@@ -739,6 +739,20 @@
       "path": "/api/v0.2/traces",
       "verb": "POST"
     },
+    {
+      "data": null,
+      "headers": {
+        "Accept-Encoding": "gzip",
+        "Content-Encoding": "gzip",
+        "Content-Length": "<redacted from snapshot>",
+        "Content-Type": "application/json",
+        "Dd-Api-Key": "abcdefghijklmnopqrstuvwxyz012345",
+        "Host": "recorder:8080",
+        "User-Agent": "<redacted from snapshot>"
+      },
+      "path": "/api/v0.2/stats",
+      "verb": "POST"
+    },
     {
       "data": {
         "series": [

aws/logs_monitoring/trace_forwarder/cmd/trace/main.go

@@ -145,9 +145,16 @@ func sendTracesToIntake(tracePayloads []*pb.TracePayload) error {
 			fmt.Printf("Failed to send traces with error %v\n", err)
 			hadErr = true
 		}
+		stats := apm.ComputeAPMStats(tracePayload)
+		err = edgeConnection.SendStats(context.Background(), stats, 3)
+		if err != nil {
+			fmt.Printf("Failed to send trace stats with error %v\n", err)
+			hadErr = true
+		}
 	}
+
 	if hadErr {
-		return errors.New("Failed to send traces to intake")
+		return errors.New("Failed to send traces or stats to intake")
 	}
 	return nil
 }