Fix bug that the agent heart beats too frequently (#4640)

* Fix bug that the agent heart beats too frequently

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

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/Config.java

@@ -117,9 +117,9 @@ public class Config {
          */
         public static long GRPC_CHANNEL_CHECK_INTERVAL = 30;
         /**
-         * service and endpoint registry check interval
+         * The period in which the agent report a heartbeat to the backend.
          */
-        public static long APP_AND_SERVICE_REGISTER_CHECK_INTERVAL = 3;
+        public static long HEARTBEAT_PERIOD = 30;
         /**
          * Collector skywalking trace receiver service addresses.
          */

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/ServiceManagementClient.java

@@ -51,7 +51,7 @@ public class ServiceManagementClient implements BootService, Runnable, GRPCChann
 
     private volatile GRPCChannelStatus status = GRPCChannelStatus.DISCONNECT;
     private volatile ManagementServiceGrpc.ManagementServiceBlockingStub managementServiceBlockingStub;
-    private volatile ScheduledFuture<?> serviceRegisterFuture;
+    private volatile ScheduledFuture<?> heartbeatFuture;
     private volatile boolean instancePropertiesSubmitted = false;
 
     @Override
@@ -85,13 +85,13 @@ public class ServiceManagementClient implements BootService, Runnable, GRPCChann
 
     @Override
     public void boot() {
-        serviceRegisterFuture = Executors.newSingleThreadScheduledExecutor(
-            new DefaultNamedThreadFactory("ServiceRegisterClient")
+        heartbeatFuture = Executors.newSingleThreadScheduledExecutor(
+            new DefaultNamedThreadFactory("ServiceManagementClient")
         ).scheduleAtFixedRate(
             new RunnableWithExceptionProtection(
                 this,
                 t -> logger.error("unexpected exception.", t)
-            ), 0, Config.Collector.APP_AND_SERVICE_REGISTER_CHECK_INTERVAL,
+            ), 0, Config.Collector.HEARTBEAT_PERIOD,
             TimeUnit.SECONDS
         );
     }
@@ -102,14 +102,14 @@ public class ServiceManagementClient implements BootService, Runnable, GRPCChann
 
     @Override
     public void shutdown() {
-        serviceRegisterFuture.cancel(true);
+        heartbeatFuture.cancel(true);
     }
 
     @Override
     public void run() {
         logger.debug("ServiceManagementClient running, status:{}.", status);
 
-        while (GRPCChannelStatus.CONNECTED.equals(status)) {
+        if (GRPCChannelStatus.CONNECTED.equals(status)) {
             try {
                 if (managementServiceBlockingStub != null) {
                     if (!instancePropertiesSubmitted) {

docs/en/setup/service-agent/java-agent/README.md

@@ -85,7 +85,7 @@ property key | Description | Default |
 `agent.operation_name_threshold `|The operationName max length, setting this value > 190 is not recommended.|`150`|
 `agent.keep_tracing`|Keep tracing even the backend is not available if this value is `true`.|`false`|
 `collector.grpc_channel_check_interval`|grpc channel status check interval.|`30`|
-`collector.app_and_service_register_check_interval`|application and service registry check interval.|`3`|
+`collector.heartbeat_period`|agent heartbeat report period. Unit, second.|`30`|
 `collector.backend_service`|Collector SkyWalking trace receiver service addresses.|`127.0.0.1:11800`|
 `collector.grpc_upstream_timeout`|How long grpc client will timeout in sending data to upstream. Unit is second.|`30` seconds|
 `collector.get_profile_task_interval`|Sniffer get profile task list interval.|`20`|
@@ -176,4 +176,4 @@ If you are interested in plugin compatible tests or agent performance, see the f
 
 # Notice
 ¹ Due to gRPC didn't support JDK 1.6 since 2018, SkyWalking abandoned the JDK 6/7 supports in all 7.x releases. 
-But, with gRPC back forward compatibility(at least for now), all SkyWalking 6.x agents could work with 7.x, including the agent and backend.
+But, with gRPC back forward compatibility(at least for now), all SkyWalking 6.x agents could work with 7.x, including the agent and backend.

test/plugin/containers/jvm-container/docker/run.sh

@@ -64,7 +64,7 @@ healthCheck http://localhost:12800/receiveData
 # start applications
 export agent_opts="-javaagent:${SCENARIO_HOME}/agent/skywalking-agent.jar
     -Dskywalking.collector.grpc_channel_check_interval=2
-    -Dskywalking.collector.app_and_service_register_check_interval=2
+    -Dskywalking.collector.heartbeat_period=2
     -Dskywalking.collector.discovery_check_interval=2
     -Dskywalking.collector.backend_service=localhost:19876
     -Dskywalking.agent.service_name=${SCENARIO_NAME}

test/plugin/containers/tomcat-container/docker/catalina.sh

@@ -109,7 +109,7 @@ echo "${AGENT_FILE_PATH}/skywalking-agent.jar"
 if [ -f "${AGENT_FILE_PATH}/skywalking-agent.jar" ]; then
     CATALINA_OPTS="$CATALINA_OPTS -javaagent:${AGENT_FILE_PATH}/skywalking-agent.jar
     -Dskywalking.collector.grpc_channel_check_interval=2
-    -Dskywalking.collector.app_and_service_register_check_interval=2
+    -Dskywalking.collector.heartbeat_period=2
     -Dskywalking.collector.discovery_check_interval=2
     -Dskywalking.collector.backend_service=localhost:19876
     -Dskywalking.agent.service_name=${SCENARIO_NAME}