Polish mesh data dispatcher: don't generate Instance/Endpoint metrics if they are empty. (#12762)

Author: wankai123

docs/en/changes/changes.md

@@ -18,6 +18,7 @@
 * The index type `BanyanDB.IndexRule.IndexType#TREE` is removed. All indices are using `IndexType#INVERTED` now.
 * Add max query size settings to BanyanDB.
 * Fix "BanyanDBTraceQueryDAO.queryBasicTraces" doesn't support querying by "trace_id".
+* Polish mesh data dispatcher: don't generate Instance/Endpoint metrics if they are empty.
 
 #### UI
 

oap-server/server-receiver-plugin/skywalking-mesh-receiver-plugin/src/main/java/org/apache/skywalking/aop/server/receiver/mesh/TelemetryDataDispatcher.java

@@ -167,15 +167,21 @@ private static void dispatchTCPMetrics(TCPServiceMeshMetric.Builder metrics) {
 
         if (org.apache.skywalking.apm.network.common.v3.DetectPoint.server.equals(metrics.getDetectPoint())) {
             toTCPService(metrics, minuteTimeBucket);
-            toTCPServiceInstance(metrics, minuteTimeBucket);
-            toTCPServiceInstanceTraffic(metrics, minuteTimeBucket);
+            // Don't generate instance metrics, if no dest instance.
+            if (StringUtil.isNotEmpty(metrics.getDestServiceInstance())) {
+                toTCPServiceInstance(metrics, minuteTimeBucket);
+                toTCPServiceInstanceTraffic(metrics, minuteTimeBucket);
+            }
         }
 
         String sourceService = metrics.getSourceServiceName();
         // Don't generate relation, if no source.
         if (StringUtil.isNotEmpty(sourceService)) {
             toTCPServiceRelation(metrics, minuteTimeBucket);
-            toTCPServiceInstanceRelation(metrics, minuteTimeBucket);
+            // Don't generate instance relation, if no source instance.
+            if (StringUtil.isNotEmpty(metrics.getSourceServiceInstance())) {
+                toTCPServiceInstanceRelation(metrics, minuteTimeBucket);
+            }
         }
     }
 
@@ -184,16 +190,25 @@ static void dispatchHTTPMetrics(HTTPServiceMeshMetric.Builder metrics) {
 
         if (org.apache.skywalking.apm.network.common.v3.DetectPoint.server.equals(metrics.getDetectPoint())) {
             toService(metrics, minuteTimeBucket);
-            toServiceInstance(metrics, minuteTimeBucket);
-            toServiceInstanceTraffic(metrics, minuteTimeBucket);
-            toEndpoint(metrics, minuteTimeBucket);
+            // Don't generate instance metrics, if no dest instance.
+            if (StringUtil.isNotEmpty(metrics.getDestServiceInstance())) {
+                toServiceInstance(metrics, minuteTimeBucket);
+                toServiceInstanceTraffic(metrics, minuteTimeBucket);
+            }
+            // Don't generate endpoint metrics, if no endpoint.
+            if (StringUtil.isNotEmpty(metrics.getEndpoint())) {
+                toEndpoint(metrics, minuteTimeBucket);
+            }
         }
 
         String sourceService = metrics.getSourceServiceName();
         // Don't generate relation, if no source.
         if (StringUtil.isNotEmpty(sourceService)) {
             toServiceRelation(metrics, minuteTimeBucket);
-            toServiceInstanceRelation(metrics, minuteTimeBucket);
+            // Don't generate instance relation, if no source instance.
+            if (StringUtil.isNotEmpty(metrics.getSourceServiceInstance())) {
+                toServiceInstanceRelation(metrics, minuteTimeBucket);
+            }
         }
     }