Provide `listMetrics` GraphQL query service. (#5866)

* Provide `listMetrics` GraphQL query service.

* Update chagnelog.

CHANGES.md

@@ -27,6 +27,7 @@ Release Notes.
 * Add the thread pool to the Kafka fetcher to increase the performance.
 * Add `contain` and `not contain` OPS in OAL.
 * Add Envoy ALS analyzer based on metadata exchange.
+* Add `listMetrics` GraphQL query. 
 * Support keeping collecting the slowly segments in the sampling mechanism.
 * Support choose files to active the meter analyzer.
 * Support nested class definition in the Service, ServiceInstance, Endpoint, ServiceRelation, and ServiceInstanceRelation sources.

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/query/MetricDefinition.java

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.apache.skywalking.oap.server.core.query;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.apache.skywalking.oap.server.core.query.enumeration.MetricsType;
+
+/**
+ * Define the metrics provided in the OAP server.
+ *
+ * @since 8.3.0
+ */
+@Setter
+@Getter
+@NoArgsConstructor
+@AllArgsConstructor
+public class MetricDefinition {
+    private String name;
+    private MetricsType type;
+    /**
+     * Catalog includes SERVICE_CATALOG,SERVICE_INSTANCE_CATALOG,ENDPOINT_CATALOG,
+     * SERVICE_RELATION_CATALOG,SERVICE_INSTANCE_RELATION_CATALOG_NAME,ENDPOINT_RELATION_CATALOG_NAME
+     */
+    private String catalog;
+}

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/query/MetricsMetadataQueryService.java

@@ -18,8 +18,12 @@
 
 package org.apache.skywalking.oap.server.core.query;
 
+import java.util.List;
 import java.util.Optional;
+import java.util.stream.Collectors;
+import org.apache.skywalking.apm.util.StringUtil;
 import org.apache.skywalking.oap.server.core.query.enumeration.MetricsType;
+import org.apache.skywalking.oap.server.core.source.DefaultScopeDefine;
 import org.apache.skywalking.oap.server.core.storage.annotation.ValueColumnMetadata;
 import org.apache.skywalking.oap.server.library.module.Service;
 
@@ -48,4 +52,21 @@ public class MetricsMetadataQueryService implements Service {
             return MetricsType.UNKNOWN;
         }
     }
+
+    public List<MetricDefinition> listMetrics(String regex) {
+        return ValueColumnMetadata.INSTANCE.getAllMetadata()
+                                           .entrySet()
+                                           .stream()
+                                           .filter(
+                                               metadata ->
+                                                   StringUtil.isNotEmpty(regex) ?
+                                                       metadata.getKey().matches(regex) : true)
+                                           .map(metadata -> new MetricDefinition(
+                                                    metadata.getKey(),
+                                                    typeOfMetrics(metadata.getKey()),
+                                                    DefaultScopeDefine.catalogOf(metadata.getValue().getScopeId())
+                                                )
+                                           )
+                                           .collect(Collectors.toList());
+    }
 }

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/source/DefaultScopeDefine.java

@@ -295,6 +295,34 @@ public class DefaultScopeDefine {
         return ENDPOINT_RELATION_CATALOG.containsKey(scopeId);
     }
 
+    /**
+     * Get the catalog string name of the given scope
+     *
+     * @param scope id of the source scope.
+     * @return literal string name of the catalog owning the scope.
+     */
+    public static String catalogOf(int scope) {
+        if (inServiceCatalog(scope)) {
+            return SERVICE_CATALOG_NAME;
+        }
+        if (inServiceInstanceCatalog(scope)) {
+            return SERVICE_INSTANCE_CATALOG_NAME;
+        }
+        if (inEndpointCatalog(scope)) {
+            return ENDPOINT_CATALOG_NAME;
+        }
+        if (inServiceRelationCatalog(scope)) {
+            return SERVICE_RELATION_CATALOG_NAME;
+        }
+        if (inServiceInstanceRelationCatalog(scope)) {
+            return SERVICE_INSTANCE_RELATION_CATALOG_NAME;
+        }
+        if (inEndpointRelationCatalog(scope)) {
+            return ENDPOINT_RELATION_CATALOG_NAME;
+        }
+        return "UNKNOWN";
+    }
+
     /**
      * Get the default columns defined in Scope. All those columns will forward to persistent entity.
      *

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/storage/annotation/ValueColumnMetadata.java

@@ -41,8 +41,9 @@ public enum ValueColumnMetadata {
                             String valueCName,
                             Column.ValueDataType dataType,
                             Function function,
-                            int defaultValue) {
-        mapping.putIfAbsent(modelName, new ValueColumn(valueCName, dataType, function, defaultValue));
+                            int defaultValue,
+                            int scopeId) {
+        mapping.putIfAbsent(modelName, new ValueColumn(valueCName, dataType, function, defaultValue, scopeId));
     }
 
     /**
@@ -63,10 +64,20 @@ public enum ValueColumnMetadata {
         return findColumn(metricsName).defaultValue;
     }
 
+    /**
+     * @return metric metadata if found
+     */
     public Optional<ValueColumn> readValueColumnDefinition(String metricsName) {
         return Optional.ofNullable(mapping.get(metricsName));
     }
 
+    /**
+     * @return all metrics metadata.
+     */
+    public Map<String, ValueColumn> getAllMetadata() {
+        return mapping;
+    }
+
     private ValueColumn findColumn(String metricsName) {
         ValueColumn column = mapping.get(metricsName);
         if (column == null) {
@@ -82,5 +93,6 @@ public enum ValueColumnMetadata {
         private final Column.ValueDataType dataType;
         private final Function function;
         private final int defaultValue;
+        private final int scopeId;
     }
 }

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/storage/model/StorageModels.java

@@ -56,7 +56,7 @@ public class StorageModels implements IModelManager, ModelCreator, ModelManipula
 
         List<ModelColumn> modelColumns = new ArrayList<>();
         List<ExtraQueryIndex> extraQueryIndices = new ArrayList<>();
-        retrieval(aClass, storage.getModelName(), modelColumns, extraQueryIndices);
+        retrieval(aClass, storage.getModelName(), modelColumns, extraQueryIndices, scopeId);
 
         Model model = new Model(
             storage.getModelName(), modelColumns, extraQueryIndices, scopeId,
@@ -91,10 +91,11 @@ public class StorageModels implements IModelManager, ModelCreator, ModelManipula
     /**
      * Read model column metadata based on the class level definition.
      */
-    private void retrieval(Class<?> clazz,
-                           String modelName,
-                           List<ModelColumn> modelColumns,
-                           List<ExtraQueryIndex> extraQueryIndices) {
+    private void retrieval(final Class<?> clazz,
+                           final String modelName,
+                           final List<ModelColumn> modelColumns,
+                           final List<ExtraQueryIndex> extraQueryIndices,
+                           final int scopeId) {
         if (log.isDebugEnabled()) {
             log.debug("Analysis {} to generate Model.", clazz.getName());
         }
@@ -131,7 +132,7 @@ public class StorageModels implements IModelManager, ModelCreator, ModelManipula
                 if (column.dataType().isValue()) {
                     ValueColumnMetadata.INSTANCE.putIfAbsent(
                         modelName, column.columnName(), column.dataType(), column.function(),
-                        column.defaultValue()
+                        column.defaultValue(), scopeId
                     );
                 }
 
@@ -152,7 +153,7 @@ public class StorageModels implements IModelManager, ModelCreator, ModelManipula
         }
 
         if (Objects.nonNull(clazz.getSuperclass())) {
-            retrieval(clazz.getSuperclass(), modelName, modelColumns, extraQueryIndices);
+            retrieval(clazz.getSuperclass(), modelName, modelColumns, extraQueryIndices, scopeId);
         }
     }
 

oap-server/server-core/src/test/java/org/apache/skywalking/oap/server/core/storage/query/MetricsQueryUtilTest.java

@@ -37,6 +37,7 @@ import org.junit.runners.Parameterized;
 
 import static com.google.common.collect.ImmutableMap.of;
 import static java.util.Arrays.asList;
+import static org.apache.skywalking.oap.server.core.source.DefaultScopeDefine.SERVICE;
 import static org.apache.skywalking.oap.server.core.storage.annotation.Column.ValueDataType.LABELED_VALUE;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.Is.is;
@@ -108,7 +109,7 @@ public class MetricsQueryUtilTest {
     @Before
     public void setup() {
         ValueColumnMetadata.INSTANCE.putIfAbsent(
-            MODULE_NAME, "value", LABELED_VALUE, Function.None, DEFAULT_VALUE
+            MODULE_NAME, "value", LABELED_VALUE, Function.None, DEFAULT_VALUE, SERVICE
         );
     }
 

oap-server/server-query-plugin/query-graphql-plugin/src/main/java/org/apache/skywalking/oap/query/graphql/resolver/MetricsQuery.java

@@ -26,6 +26,7 @@ import java.util.List;
 import org.apache.skywalking.oap.server.core.CoreModule;
 import org.apache.skywalking.oap.server.core.analysis.metrics.DataTable;
 import org.apache.skywalking.oap.server.core.query.AggregationQueryService;
+import org.apache.skywalking.oap.server.core.query.MetricDefinition;
 import org.apache.skywalking.oap.server.core.query.MetricsMetadataQueryService;
 import org.apache.skywalking.oap.server.core.query.MetricsQueryService;
 import org.apache.skywalking.oap.server.core.query.PointOfTime;
@@ -99,6 +100,16 @@ public class MetricsQuery implements GraphQLQueryResolver {
         return getMetricsMetadataQueryService().typeOfMetrics(name);
     }
 
+    /**
+     * Get the list of all available metrics in the current OAP server.
+     *
+     * @param regex to filter the metrics by name, if existing.
+     * @return all available metrics.
+     */
+    public List<MetricDefinition> listMetrics(String regex) {
+        return getMetricsMetadataQueryService().listMetrics(regex);
+    }
+
     /**
      * Read metrics single value in the duration of required metrics
      */

query-protocol @ d3608e86

-Subproject commit 77afd814040c5532e5e4a68f5ef1694a80dad0c4
+Subproject commit d3608e86f7c9aaf54aa4ad2c8d2afd09d0680dd6