From 3a31cbe222676e85ef834735b26a64e791c8f9c3 Mon Sep 17 00:00:00 2001
From: Kai <wankai123@foxmail.com>
Date: Thu, 10 Mar 2022 13:40:23 +0800
Subject: [PATCH] return all Layer definition names within OAP (#8651)

---
 .../oap/server/core/query/MetadataQueryService.java    | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/query/MetadataQueryService.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/query/MetadataQueryService.java
index 282a9d7db3..ee75a5d343 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/query/MetadataQueryService.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/query/MetadataQueryService.java
@@ -20,12 +20,13 @@ package org.apache.skywalking.oap.server.core.query;
 
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.HashSet;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Collectors;
 import org.apache.skywalking.oap.server.core.Const;
 import org.apache.skywalking.oap.server.core.analysis.IDManager;
+import org.apache.skywalking.oap.server.core.analysis.Layer;
 import org.apache.skywalking.oap.server.core.query.type.Endpoint;
 import org.apache.skywalking.oap.server.core.query.type.EndpointInfo;
 import org.apache.skywalking.oap.server.core.query.type.Service;
@@ -51,12 +52,7 @@ public class MetadataQueryService implements org.apache.skywalking.oap.server.li
     }
 
     public Set<String> listLayers() throws IOException {
-        Set<String> layers = new HashSet<>();
-        getMetadataQueryDAO().listServices(null, null).forEach(service -> {
-            layers.addAll(service.getLayers());
-
-        });
-        return layers;
+        return Arrays.stream(Layer.values()).filter(layer -> layer.value() > 0).map(Layer::name).collect(Collectors.toSet());
     }
 
     public List<Service> listServices(final String layer, final String group) throws IOException {