supprt gRPC alarm hook. (#4344)

* support gRPC hook.

* revert submodule commit.

* revert submodule commitid.

* finish logical.

* remove author anonatation.

* fix ci.

* revert submodule.

* update logical.

* update logical.

* update logical.

* fix

* fix

* fix empty settings.

* fix.

Co-authored-by: 吴晟 Wu Sheng <wu.sheng@foxmail.com>

docs/en/setup/backend/backend-alarm.md

@@ -3,6 +3,7 @@ Alarm core is driven by a collection of rules, which are defined in `config/alar
 There are two parts in alarm rule definition.
 1. [Alarm rules](#rules). They define how metrics alarm should be triggered, what conditions should be considered.
 1. [Webhooks](#webhook). The list of web service endpoint, which should be called after the alarm is triggered.
+1. [gRPCHook](#gRPCHook). The host and port of remote gRPC method, which should be called after the alarm is triggered.
 
 ## Rules
 Alarm rule is constituted by following keys
@@ -113,6 +114,24 @@ Example as following
 }]
 ```
 
+## gRPCHook
+The alarm message will send through remote gRPC method by `Protobuf` content type. 
+The message format with following key information which are defined in `oap-server/server-alarm-plugin/src/main/proto/alarm-hook.proto`.
+
+Part of protocol looks as following:
+```protobuf
+message AlarmMessage {
+    int64 scopeId = 1;
+    string scope = 2;
+    string name = 3;
+    int64 id0 = 4;
+    int64 id1 = 5;
+    string ruleName = 6;
+    string alarmMessage = 7;
+    int64 startTime = 8;
+}
+```
+
 ## Update the settings dynamically
 Since 6.5.0, the alarm settings can be updated dynamically at runtime by [Dynamic Configuration](dynamic-config.md),
 which will override the settings in `alarm-settings.yml`.

oap-server/exporter/src/main/java/org/apache/skywalking/oap/server/exporter/provider/grpc/GRPCExporter.java

@@ -25,8 +25,6 @@ import java.util.List;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
-import lombok.AccessLevel;
-import lombok.Getter;
 import org.apache.skywalking.apm.commons.datacarrier.DataCarrier;
 import org.apache.skywalking.apm.commons.datacarrier.consumer.IConsumer;
 import org.apache.skywalking.oap.server.core.analysis.metrics.DoubleValueHolder;
@@ -36,6 +34,7 @@ import org.apache.skywalking.oap.server.core.analysis.metrics.Metrics;
 import org.apache.skywalking.oap.server.core.analysis.metrics.MetricsMetaInfo;
 import org.apache.skywalking.oap.server.core.analysis.metrics.MultiIntValuesHolder;
 import org.apache.skywalking.oap.server.core.analysis.metrics.WithMetadata;
+import org.apache.skywalking.oap.server.core.exporter.ExportData;
 import org.apache.skywalking.oap.server.core.exporter.ExportEvent;
 import org.apache.skywalking.oap.server.core.exporter.MetricValuesExportService;
 import org.apache.skywalking.oap.server.exporter.grpc.ExportMetricValue;
@@ -46,10 +45,11 @@ import org.apache.skywalking.oap.server.exporter.grpc.SubscriptionsResp;
 import org.apache.skywalking.oap.server.exporter.grpc.ValueType;
 import org.apache.skywalking.oap.server.exporter.provider.MetricFormatter;
 import org.apache.skywalking.oap.server.library.client.grpc.GRPCClient;
+import org.apache.skywalking.oap.server.library.util.GRPCStreamStatus;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class GRPCExporter extends MetricFormatter implements MetricValuesExportService, IConsumer<GRPCExporter.ExportData> {
+public class GRPCExporter extends MetricFormatter implements MetricValuesExportService, IConsumer<ExportData> {
     private static final Logger logger = LoggerFactory.getLogger(GRPCExporter.class);
 
     private GRPCExporterSetting setting;
@@ -101,26 +101,28 @@ public class GRPCExporter extends MetricFormatter implements MetricValuesExportS
             return;
         }
 
-        ExportStatus status = new ExportStatus();
+        GRPCStreamStatus status = new GRPCStreamStatus();
-        StreamObserver<ExportMetricValue> streamObserver = exportServiceFutureStub.withDeadlineAfter(10, TimeUnit.SECONDS)
+        StreamObserver<ExportMetricValue> streamObserver = exportServiceFutureStub.withDeadlineAfter(
-                                                                                  .export(new StreamObserver<ExportResponse>() {
+            10, TimeUnit.SECONDS)
-                                                                                      @Override
+                                                                                  .export(
-                                                                                      public void onNext(
+                                                                                      new StreamObserver<ExportResponse>() {
-                                                                                          ExportResponse response) {
+                                                                                          @Override
+                                                                                          public void onNext(
+                                                                                              ExportResponse response) {
 
-                                                                                      }
+                                                                                          }
 
-                                                                                      @Override
+                                                                                          @Override
-                                                                                      public void onError(
+                                                                                          public void onError(
-                                                                                          Throwable throwable) {
+                                                                                              Throwable throwable) {
-                                                                                          status.done();
+                                                                                              status.done();
-                                                                                      }
+                                                                                          }
 
-                                                                                      @Override
+                                                                                          @Override
-                                                                                      public void onCompleted() {
+                                                                                          public void onCompleted() {
-                                                                                          status.done();
+                                                                                              status.done();
-                                                                                      }
+                                                                                          }
-                                                                                  });
+                                                                                      });
         AtomicInteger exportNum = new AtomicInteger();
         data.forEach(row -> {
             ExportMetricValue.Builder builder = ExportMetricValue.newBuilder();
@@ -167,9 +169,8 @@ public class GRPCExporter extends MetricFormatter implements MetricValuesExportS
 
         long sleepTime = 0;
         long cycle = 100L;
-        /**
+
-         * For memory safe of oap, we must wait for the peer confirmation.
+        //For memory safe of oap, we must wait for the peer confirmation.
-         */
         while (!status.isDone()) {
             try {
                 sleepTime += cycle;
@@ -178,14 +179,18 @@ public class GRPCExporter extends MetricFormatter implements MetricValuesExportS
             }
 
             if (sleepTime > 2000L) {
-                logger.warn("Export {} metrics to {}:{}, wait {} milliseconds.", exportNum.get(), setting.getTargetHost(), setting
+                logger.warn(
-                    .getTargetPort(), sleepTime);
+                    "Export {} metrics to {}:{}, wait {} milliseconds.", exportNum.get(), setting.getTargetHost(),
+                    setting
+                        .getTargetPort(), sleepTime
+                );
                 cycle = 2000L;
             }
         }
 
-        logger.debug("Exported {} metrics to {}:{} in {} milliseconds.", exportNum.get(), setting.getTargetHost(), setting
+        logger.debug(
-            .getTargetPort(), sleepTime);
+            "Exported {} metrics to {}:{} in {} milliseconds.", exportNum.get(), setting.getTargetHost(), setting
+                .getTargetPort(), sleepTime);
     }
 
     @Override
@@ -197,27 +202,4 @@ public class GRPCExporter extends MetricFormatter implements MetricValuesExportS
     public void onExit() {
 
     }
-
-    @Getter(AccessLevel.PRIVATE)
-    public class ExportData {
-        private MetricsMetaInfo meta;
-        private Metrics metrics;
-
-        public ExportData(MetricsMetaInfo meta, Metrics metrics) {
-            this.meta = meta;
-            this.metrics = metrics;
-        }
-    }
-
-    private class ExportStatus {
-        private boolean done = false;
-
-        private void done() {
-            done = true;
-        }
-
-        public boolean isDone() {
-            return done;
-        }
-    }
 }

oap-server/exporter/src/test/java/org/apache/skywalking/oap/server/exporter/provider/grpc/GRPCExporterTest.java

@@ -24,6 +24,7 @@ import java.util.LinkedList;
 import java.util.List;
 import org.apache.skywalking.oap.server.core.analysis.metrics.MetricsMetaInfo;
 import org.apache.skywalking.oap.server.core.analysis.metrics.WithMetadata;
+import org.apache.skywalking.oap.server.core.exporter.ExportData;
 import org.apache.skywalking.oap.server.core.exporter.ExportEvent;
 import org.apache.skywalking.oap.server.core.source.DefaultScopeDefine;
 import org.apache.skywalking.oap.server.exporter.grpc.MetricExportServiceGrpc;
@@ -97,12 +98,12 @@ public class GRPCExporterTest {
         exporter.onExit();
     }
 
-    private List<GRPCExporter.ExportData> dataList() {
+    private List<ExportData> dataList() {
-        List<GRPCExporter.ExportData> dataList = new LinkedList<>();
+        List<ExportData> dataList = new LinkedList<>();
-        dataList.add(exporter.new ExportData(metaInfo, new MockMetrics()));
+        dataList.add(new ExportData(metaInfo, new MockMetrics()));
-        dataList.add(exporter.new ExportData(metaInfo, new MockIntValueMetrics()));
+        dataList.add(new ExportData(metaInfo, new MockIntValueMetrics()));
-        dataList.add(exporter.new ExportData(metaInfo, new MockLongValueMetrics()));
+        dataList.add(new ExportData(metaInfo, new MockLongValueMetrics()));
-        dataList.add(exporter.new ExportData(metaInfo, new MockDoubleValueMetrics()));
+        dataList.add(new ExportData(metaInfo, new MockDoubleValueMetrics()));
         return dataList;
     }
 }

oap-server/server-alarm-plugin/pom.xml

@@ -27,6 +27,7 @@
     <modelVersion>4.0.0</modelVersion>
 
     <artifactId>server-alarm-plugin</artifactId>
+
     <dependencies>
         <dependency>
             <groupId>org.apache.skywalking</groupId>
@@ -38,7 +39,40 @@
             <artifactId>library-util</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>io.grpc</groupId>
+            <artifactId>grpc-testing</artifactId>
+        </dependency>
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.xolstice.maven.plugins</groupId>
+                <artifactId>protobuf-maven-plugin</artifactId>
+                <version>${protobuf-maven-plugin.version}</version>
+                <configuration>
+                    <!--
+                      The version of protoc must match protobuf-java. If you don't depend on
+                      protobuf-java directly, you will be transitively depending on the
+                      protobuf-java version that grpc depends on.
+                    -->
+                    <protocArtifact>com.google.protobuf:protoc:${com.google.protobuf.protoc.version}:exe:${os.detected.classifier}
+                    </protocArtifact>
+                    <pluginId>grpc-java</pluginId>
+                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:${protoc-gen-grpc-java.plugin.version}:exe:${os.detected.classifier}
+                    </pluginArtifact>
+                </configuration>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>compile</goal>
+                            <goal>compile-custom</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
 
 </project>

oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/AlarmRulesWatcher.java

@@ -18,23 +18,22 @@
 
 package org.apache.skywalking.oap.server.core.alarm.provider;
 
-import lombok.Getter;
-import lombok.extern.slf4j.Slf4j;
-import org.apache.skywalking.oap.server.configuration.api.ConfigChangeWatcher;
-import org.apache.skywalking.oap.server.core.Const;
-import org.apache.skywalking.oap.server.core.alarm.AlarmModule;
-import org.apache.skywalking.oap.server.library.module.ModuleProvider;
-
 import java.io.StringReader;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import lombok.Getter;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.skywalking.oap.server.configuration.api.ConfigChangeWatcher;
+import org.apache.skywalking.oap.server.core.Const;
+import org.apache.skywalking.oap.server.core.alarm.AlarmModule;
+import org.apache.skywalking.oap.server.core.alarm.provider.grpc.GRPCAlarmSetting;
+import org.apache.skywalking.oap.server.library.module.ModuleProvider;
 
 /**
- * Alarm rules' settings can be dynamically updated via configuration center(s),
+ * Alarm rules' settings can be dynamically updated via configuration center(s), this class is responsible for
- * this class is responsible for monitoring the configuration and parsing them
+ * monitoring the configuration and parsing them into {@link Rules} and {@link #runningContext}.
- * into {@link Rules} and {@link #runningContext}.
  *
  * @since 6.5.0
  */
@@ -106,4 +105,8 @@ public class AlarmRulesWatcher extends ConfigChangeWatcher {
     public List<String> getWebHooks() {
         return this.rules.getWebhooks();
     }
+
+    public GRPCAlarmSetting getGrpchookSetting() {
+        return this.rules.getGrpchookSetting();
+    }
 }

oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/NotifyHandler.java

@@ -28,6 +28,7 @@ import org.apache.skywalking.oap.server.core.alarm.MetaInAlarm;
 import org.apache.skywalking.oap.server.core.alarm.MetricsNotify;
 import org.apache.skywalking.oap.server.core.alarm.ServiceInstanceMetaInAlarm;
 import org.apache.skywalking.oap.server.core.alarm.ServiceMetaInAlarm;
+import org.apache.skywalking.oap.server.core.alarm.provider.grpc.GRPCCallback;
 import org.apache.skywalking.oap.server.core.analysis.metrics.Metrics;
 import org.apache.skywalking.oap.server.core.analysis.metrics.MetricsMetaInfo;
 import org.apache.skywalking.oap.server.core.analysis.metrics.WithMetadata;
@@ -110,6 +111,7 @@ public class NotifyHandler implements MetricsNotify {
     public void init(AlarmCallback... callbacks) {
         List<AlarmCallback> allCallbacks = new ArrayList<>(Arrays.asList(callbacks));
         allCallbacks.add(new WebhookCallback(alarmRulesWatcher));
+        allCallbacks.add(new GRPCCallback(alarmRulesWatcher));
         core.start(allCallbacks);
     }
 

oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/Rules.java

@@ -24,6 +24,7 @@ import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.Setter;
 import lombok.ToString;
+import org.apache.skywalking.oap.server.core.alarm.provider.grpc.GRPCAlarmSetting;
 
 @Setter(AccessLevel.PUBLIC)
 @Getter(AccessLevel.PUBLIC)
@@ -31,6 +32,7 @@ import lombok.ToString;
 public class Rules {
     private List<AlarmRule> rules;
     private List<String> webhooks;
+    private GRPCAlarmSetting grpchookSetting;
 
     public Rules() {
         this.rules = new ArrayList<>();

oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/RulesReader.java

@@ -24,6 +24,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import org.apache.skywalking.oap.server.core.alarm.provider.grpc.GRPCAlarmSetting;
 import org.yaml.snakeyaml.Yaml;
 
 /**
@@ -81,6 +82,22 @@ public class RulesReader {
                     rules.getWebhooks().add((String) url);
                 });
             }
+
+            Map grpchooks = (Map) yamlData.get("gRPCHook");
+            if (grpchooks != null) {
+                GRPCAlarmSetting grpcAlarmSetting = new GRPCAlarmSetting();
+                Object targetHost = grpchooks.get("target_host");
+                if (targetHost != null) {
+                    grpcAlarmSetting.setTargetHost((String) targetHost);
+                }
+
+                Object targetPort = grpchooks.get("target_port");
+                if (targetPort != null) {
+                    grpcAlarmSetting.setTargetPort((Integer) targetPort);
+                }
+
+                rules.setGrpchookSetting(grpcAlarmSetting);
+            }
         }
 
         return rules;

oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/grpc/GRPCAlarmSetting.java

@@ -0,0 +1,36 @@
+/*
+ * 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.alarm.provider.grpc;
+
+import java.util.Objects;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.Setter;
+
+@Setter
+@Getter
+@EqualsAndHashCode
+public class GRPCAlarmSetting {
+    private String targetHost;
+    private int targetPort;
+
+    public boolean isEmptySetting() {
+        return Objects.isNull(targetHost);
+    }
+}

oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/grpc/GRPCCallback.java

@@ -0,0 +1,163 @@
+/*
+ * 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.alarm.provider.grpc;
+
+import io.grpc.stub.StreamObserver;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.skywalking.oap.server.core.alarm.AlarmCallback;
+import org.apache.skywalking.oap.server.core.alarm.AlarmMessage;
+import org.apache.skywalking.oap.server.core.alarm.grpc.AlarmServiceGrpc;
+import org.apache.skywalking.oap.server.core.alarm.grpc.Response;
+import org.apache.skywalking.oap.server.core.alarm.provider.AlarmRulesWatcher;
+import org.apache.skywalking.oap.server.library.client.grpc.GRPCClient;
+import org.apache.skywalking.oap.server.library.util.GRPCStreamStatus;
+
+/**
+ * Use SkyWalking alarm grpc API call a remote methods.
+ */
+@Slf4j
+public class GRPCCallback implements AlarmCallback {
+
+    private AlarmRulesWatcher alarmRulesWatcher;
+
+    private GRPCAlarmSetting alarmSetting;
+
+    private AlarmServiceGrpc.AlarmServiceStub alarmServiceStub;
+
+    private GRPCClient grpcClient;
+
+    public GRPCCallback(AlarmRulesWatcher alarmRulesWatcher) {
+        this.alarmRulesWatcher = alarmRulesWatcher;
+        alarmSetting = alarmRulesWatcher.getGrpchookSetting();
+
+        if (alarmSetting != null && !alarmSetting.isEmptySetting()) {
+            grpcClient = new GRPCClient(alarmSetting.getTargetHost(), alarmSetting.getTargetPort());
+            grpcClient.connect();
+            alarmServiceStub = AlarmServiceGrpc.newStub(grpcClient.getChannel());
+        }
+    }
+
+    @Override
+    public void doAlarm(List<AlarmMessage> alarmMessage) {
+
+        if (alarmSetting.isEmptySetting()) {
+            return;
+        }
+
+        // recreate gRPC client and stub if host and port configuration changed.
+        onGRPCAlarmSettingUpdated(alarmRulesWatcher.getGrpchookSetting());
+
+        GRPCStreamStatus status = new GRPCStreamStatus();
+
+        if (alarmServiceStub == null) {
+            return;
+        }
+
+        StreamObserver<org.apache.skywalking.oap.server.core.alarm.grpc.AlarmMessage> streamObserver =
+            alarmServiceStub.withDeadlineAfter(10, TimeUnit.SECONDS).doAlarm(new StreamObserver<Response>() {
+                @Override
+                public void onNext(Response response) {
+                    // ignore empty response
+                }
+
+                @Override
+                public void onError(Throwable throwable) {
+                    status.done();
+                    if (log.isDebugEnabled()) {
+                        log.debug("Send alarm message failed: {}", throwable.getMessage());
+                    }
+                }
+
+                @Override
+                public void onCompleted() {
+                    status.done();
+                    if (log.isDebugEnabled()) {
+                        log.debug("Send alarm message successful.");
+                    }
+                }
+            });
+
+        alarmMessage.forEach(message -> {
+            org.apache.skywalking.oap.server.core.alarm.grpc.AlarmMessage.Builder builder =
+                org.apache.skywalking.oap.server.core.alarm.grpc.AlarmMessage.newBuilder();
+
+            builder.setScopeId(message.getScopeId());
+            builder.setScope(message.getScope());
+            builder.setName(message.getName());
+            builder.setId0(message.getId0());
+            builder.setId1(message.getId1());
+            builder.setRuleName(message.getRuleName());
+            builder.setAlarmMessage(message.getAlarmMessage());
+            builder.setStartTime(message.getStartTime());
+
+            streamObserver.onNext(builder.build());
+        });
+
+        streamObserver.onCompleted();
+
+        long sleepTime = 0;
+        long cycle = 100L;
+
+        // For memory safe of oap, we must wait for the peer confirmation.
+        while (!status.isDone()) {
+            try {
+                sleepTime += cycle;
+                Thread.sleep(cycle);
+            } catch (InterruptedException ignored) {
+            }
+
+            if (log.isDebugEnabled()) {
+                log.debug("Send {} alarm message to {}:{}.", alarmMessage.size(),
+                          alarmSetting.getTargetHost(), alarmSetting.getTargetPort()
+                );
+            }
+
+            if (sleepTime > 2000L) {
+                log.warn("Send {} alarm message to {}:{}, wait {} milliseconds.", alarmMessage.size(),
+                         alarmSetting.getTargetHost(), alarmSetting.getTargetPort(), sleepTime
+                );
+                cycle = 2000L;
+            }
+        }
+    }
+
+    private void onGRPCAlarmSettingUpdated(GRPCAlarmSetting grpcAlarmSetting) {
+        if (grpcAlarmSetting == null) {
+            if (grpcClient != null) {
+                grpcClient.shutdown();
+            }
+            alarmServiceStub = null;
+            alarmSetting = null;
+
+            log.warn("gRPC alarm hook settings about host is empty, shutdown the old gRPC client.");
+            return;
+        }
+
+        if (!grpcAlarmSetting.equals(alarmSetting)) {
+            if (grpcClient != null) {
+                grpcClient.shutdown();
+            }
+            grpcClient = new GRPCClient(grpcAlarmSetting.getTargetHost(), grpcAlarmSetting.getTargetPort());
+            grpcClient.connect();
+            alarmServiceStub = AlarmServiceGrpc.newStub(grpcClient.getChannel());
+        }
+    }
+}

oap-server/server-alarm-plugin/src/main/proto/alarm-hook.proto

@@ -0,0 +1,42 @@
+/*
+ * 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.
+ *
+ */
+
+syntax = "proto3";
+
+option java_multiple_files = true;
+option java_package = "org.apache.skywalking.oap.server.core.alarm.grpc";
+
+service AlarmService {
+    rpc doAlarm (stream AlarmMessage) returns (Response) {
+    }
+}
+
+message AlarmMessage {
+    int64 scopeId = 1;
+    string scope = 2;
+    string name = 3;
+    int64 id0 = 4;
+    int64 id1 = 5;
+    string ruleName = 6;
+    string alarmMessage = 7;
+    int64 startTime = 8;
+}
+
+message Response {
+}
+

oap-server/server-alarm-plugin/src/test/java/org/apache/skywalking/oap/server/core/alarm/provider/AlarmRulesWatcherTest.java

@@ -31,6 +31,7 @@ import org.mockito.Spy;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.spy;
@@ -78,6 +79,8 @@ public class AlarmRulesWatcherTest {
 
         assertEquals(2, alarmRulesWatcher.getRules().size());
         assertEquals(2, alarmRulesWatcher.getWebHooks().size());
+        assertNotNull(alarmRulesWatcher.getGrpchookSetting());
+        assertEquals(9888, alarmRulesWatcher.getGrpchookSetting().getTargetPort());
         assertEquals(2, alarmRulesWatcher.getRunningContext().size());
     }
 
@@ -92,6 +95,7 @@ public class AlarmRulesWatcherTest {
 
         assertEquals(0, alarmRulesWatcher.getRules().size());
         assertEquals(0, alarmRulesWatcher.getWebHooks().size());
+        assertNull(alarmRulesWatcher.getGrpchookSetting());
         assertEquals(0, alarmRulesWatcher.getRunningContext().size());
     }
 

oap-server/server-alarm-plugin/src/test/java/org/apache/skywalking/oap/server/core/alarm/provider/grpc/AlarmMockReceiver.java

@@ -0,0 +1,72 @@
+/*
+ * 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.alarm.provider.grpc;
+
+import io.grpc.stub.StreamObserver;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.skywalking.oap.server.core.alarm.grpc.AlarmMessage;
+import org.apache.skywalking.oap.server.core.alarm.grpc.AlarmServiceGrpc;
+import org.apache.skywalking.oap.server.core.alarm.grpc.Response;
+import org.apache.skywalking.oap.server.library.server.ServerException;
+import org.apache.skywalking.oap.server.library.server.grpc.GRPCHandler;
+import org.apache.skywalking.oap.server.library.server.grpc.GRPCServer;
+
+@Slf4j
+public class AlarmMockReceiver {
+    public static void main(String[] args) throws ServerException, InterruptedException {
+        GRPCServer server = new GRPCServer("localhost", 9888);
+        server.initialize();
+        server.addHandler(new MockAlarmHandler());
+        server.start();
+
+        while (true) {
+            Thread.sleep(20000L);
+        }
+    }
+
+    public static class MockAlarmHandler extends AlarmServiceGrpc.AlarmServiceImplBase implements GRPCHandler {
+
+        @Override public StreamObserver<AlarmMessage> doAlarm(StreamObserver<Response> responseObserver) {
+            return new StreamObserver<AlarmMessage>() {
+                @Override
+                public void onNext(AlarmMessage value) {
+                    log.info("received alarm message: {}", value.toString());
+                }
+
+                @Override
+                public void onError(Throwable throwable) {
+                    responseObserver.onError(throwable);
+                    if (log.isDebugEnabled()) {
+                        log.debug("received alarm message error.");
+                    }
+                    responseObserver.onCompleted();
+                }
+
+                @Override
+                public void onCompleted() {
+                    responseObserver.onNext(Response.newBuilder().build());
+                    responseObserver.onCompleted();
+                    if (log.isDebugEnabled()) {
+                        log.debug("received alarm message completed.");
+                    }
+                }
+            };
+        }
+    }
+}

oap-server/server-alarm-plugin/src/test/java/org/apache/skywalking/oap/server/core/alarm/provider/grpc/GRPChookCallbackTest.java

@@ -0,0 +1,79 @@
+/*
+ * 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.alarm.provider.grpc;
+
+import com.google.common.collect.Lists;
+import java.util.List;
+import org.apache.skywalking.oap.server.core.alarm.AlarmMessage;
+import org.apache.skywalking.oap.server.core.alarm.provider.AlarmRulesWatcher;
+import org.apache.skywalking.oap.server.core.alarm.provider.Rules;
+import org.apache.skywalking.oap.server.core.query.entity.Scope;
+import org.junit.Before;
+import org.junit.Test;
+
+public class GRPChookCallbackTest {
+
+    private GRPCCallback grpcCallback;
+
+    private AlarmRulesWatcher alarmRulesWatcher;
+
+    private List<AlarmMessage> alarmMessageList;
+
+    @Before
+    public void init() throws Exception {
+        GRPCAlarmSetting setting = new GRPCAlarmSetting();
+        setting.setTargetHost("127.0.0.1");
+        setting.setTargetPort(9888);
+
+        Rules rules = new Rules();
+        rules.setGrpchookSetting(setting);
+
+        alarmRulesWatcher = new AlarmRulesWatcher(rules, null);
+        grpcCallback = new GRPCCallback(alarmRulesWatcher);
+        mockAlarmMessage();
+    }
+
+    @Test
+    public void doAlarm() {
+        grpcCallback.doAlarm(alarmMessageList);
+    }
+
+    @Test
+    public void testGauchoSettingClean() {
+        GRPCAlarmSetting grpcAlarmSetting = new GRPCAlarmSetting();
+        Rules rules = new Rules();
+        rules.setGrpchookSetting(grpcAlarmSetting);
+        alarmRulesWatcher = new AlarmRulesWatcher(rules, null);
+        grpcCallback = new GRPCCallback(alarmRulesWatcher);
+        grpcCallback.doAlarm(alarmMessageList);
+    }
+
+    private void mockAlarmMessage() {
+        AlarmMessage alarmMessage = new AlarmMessage();
+        alarmMessage.setId0(1);
+        alarmMessage.setId1(2);
+        alarmMessage.setScope(Scope.Service.name());
+        alarmMessage.setName("mock alarm message");
+        alarmMessage.setAlarmMessage("message");
+        alarmMessage.setRuleName("mock_rule");
+        alarmMessage.setStartTime(System.currentTimeMillis());
+
+        alarmMessageList = Lists.newArrayList(alarmMessage);
+    }
+}

oap-server/server-alarm-plugin/src/test/resources/alarm-settings.yml

@@ -44,3 +44,7 @@ webhooks:
   - http://127.0.0.1/notify/
   - http://127.0.0.1/go-wechat/
 
+gRPCHook:
+  target_host: 127.0.0.1
+  target_port: 9888
+

oap-server/server-bootstrap/src/main/resources/alarm-settings.yml

@@ -43,3 +43,7 @@ webhooks:
 #  - http://127.0.0.1/notify/
 #  - http://127.0.0.1/go-wechat/
 
+gRPCHook:
+#  target_host: 127.0.0.1
+#  target_port: 9888
+

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/exporter/ExportData.java

@@ -0,0 +1,34 @@
+/*
+ * 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.exporter;
+
+import lombok.Getter;
+import org.apache.skywalking.oap.server.core.analysis.metrics.Metrics;
+import org.apache.skywalking.oap.server.core.analysis.metrics.MetricsMetaInfo;
+
+@Getter
+public class ExportData {
+    private MetricsMetaInfo meta;
+    private Metrics metrics;
+
+    public ExportData(MetricsMetaInfo meta, Metrics metrics) {
+        this.meta = meta;
+        this.metrics = metrics;
+    }
+}

oap-server/server-library/library-util/src/main/java/org/apache/skywalking/oap/server/library/util/GRPCStreamStatus.java

@@ -0,0 +1,31 @@
+/*
+ * 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.library.util;
+
+import lombok.Getter;
+
+@Getter
+public class GRPCStreamStatus {
+
+    private volatile boolean done = false;
+
+    public void done() {
+        done = true;
+    }
+}