客户端经常报com.alibaba.nacos.api.exception.NacosException: java.util.concurrent.TimeoutException: Waited 3000 milliseconds异常

[john1337]

nacos-client版本为2.2.0，这个依赖版本是引入spring-cloud-starter-alibaba-nacos-config 2021.0.5.0组件间接引入的，
，nacos 服务端版本为2.2.2，在一个环境下经常报下面的异常信息：
2024-01-03 00:00:48.419 ERROR 1 --- [ask-Scheduler-1] c.a.c.n.discovery.NacosDiscoveryClient : get service name from nacos server failed.

com.alibaba.nacos.api.exception.NacosException: java.util.concurrent.TimeoutException: Waited 3000 milliseconds (plus 102747 nanoseconds delay) for com.alibaba.nacos.shaded.io.grpc.stub.ClientCalls$GrpcFuture@785f29fe[status=PENDING, info=[GrpcFuture{clientCall=ClientCallImpl{method=MethodDescriptor{fullMethodName=Request/request, type=UNARY, idempotent=false, safe=false, sampledToLocalTracing=true, requestMarshaller=com.alibaba.nacos.shaded.io.grpc.protobuf.lite.ProtoLiteUtils$MessageMarshaller@195ce0db, responseMarshaller=com.alibaba.nacos.shaded.io.grpc.protobuf.lite.ProtoLiteUtils$MessageMarshaller@2c75f128, schemaDescriptor=com.alibaba.nacos.api.grpc.auto.RequestGrpc$RequestMethodDescriptorSupplier@7668d92e}}}]]
at com.alibaba.nacos.common.remote.client.grpc.GrpcConnection.request(GrpcConnection.java:78) ~[nacos-client-2.2.0.jar:na]
at com.alibaba.nacos.common.remote.client.RpcClient.request(RpcClient.java:641) ~[nacos-client-2.2.0.jar:na]
at com.alibaba.nacos.common.remote.client.RpcClient.request(RpcClient.java:619) ~[nacos-client-2.2.0.jar:na]
at com.alibaba.nacos.client.naming.remote.gprc.NamingGrpcClientProxy.requestToServer(NamingGrpcClientProxy.java:356) ~[nacos-client-2.2.0.jar:na]
at com.alibaba.nacos.client.naming.remote.gprc.NamingGrpcClientProxy.getServiceList(NamingGrpcClientProxy.java:282) ~[nacos-client-2.2.0.jar:na]
at com.alibaba.nacos.client.naming.remote.NamingClientProxyDelegate.getServiceList(NamingClientProxyDelegate.java:162) ~[nacos-client-2.2.0.jar:na]
at com.alibaba.nacos.client.naming.NacosNamingService.getServicesOfServer(NacosNamingService.java:461) ~[nacos-client-2.2.0.jar:na]
at com.alibaba.nacos.client.naming.NacosNamingService.getServicesOfServer(NacosNamingService.java:449) ~[nacos-client-2.2.0.jar:na]
at com.alibaba.cloud.nacos.discovery.NacosServiceDiscovery.getServices(NacosServiceDiscovery.java:70) ~[spring-cloud-starter-alibaba-nacos-discovery-2021.0.5.0.jar:2021.0.5.0]
at com.alibaba.cloud.nacos.discovery.NacosDiscoveryClient.getServices(NacosDiscoveryClient.java:80) ~[spring-cloud-starter-alibaba-nacos-discovery-2021.0.5.0.jar:2021.0.5.0]
at org.springframework.cloud.client.discovery.composite.CompositeDiscoveryClient.getServices(CompositeDiscoveryClient.java:67) ~[spring-cloud-commons-3.1.5.jar:3.1.5]
at com.github.xiaoymin.knife4j.spring.gateway.discover.ServiceChangeListener.discover(ServiceChangeListener.java:40) ~[knife4j-gateway-spring-boot-starter-4.1.0.jar:na]
at jdk.internal.reflect.GeneratedMethodAccessor262.invoke(Unknown Source) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
at org.springframework.context.event.ApplicationListenerMethodAdapter.doInvoke(ApplicationListenerMethodAdapter.java:344) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.event.ApplicationListenerMethodAdapter.processEvent(ApplicationListenerMethodAdapter.java:229) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.event.ApplicationListenerMethodAdapter.onApplicationEvent(ApplicationListenerMethodAdapter.java:166) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.cloud.gateway.route.RouteRefreshListener.reset(RouteRefreshListener.java:73) ~[spring-cloud-gateway-server-3.1.4.jar:3.1.4]
at org.springframework.cloud.gateway.route.RouteRefreshListener.resetIfNeeded(RouteRefreshListener.java:68) ~[spring-cloud-gateway-server-3.1.4.jar:3.1.4]
at org.springframework.cloud.gateway.route.RouteRefreshListener.onApplicationEvent(RouteRefreshListener.java:62) ~[spring-cloud-gateway-server-3.1.4.jar:3.1.4]
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.23.jar:5.3.23]
at com.alibaba.cloud.nacos.discovery.GatewayLocatorHeartBeatPublisher.publishHeartBeat(GatewayLocatorHeartBeatPublisher.java:100) ~[spring-cloud-starter-alibaba-nacos-discovery-2021.0.5.0.jar:2021.0.5.0]
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-5.3.23.jar:5.3.23]
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) ~[na:na]
at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305) ~[na:na]
at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at java.base/java.lang.Thread.run(Thread.java:829) ~[na:na]
Caused by: java.util.concurrent.TimeoutException: Waited 3000 milliseconds (plus 102747 nanoseconds delay) for com.alibaba.nacos.shaded.io.grpc.stub.ClientCalls$GrpcFuture@785f29fe[status=PENDING, info=[GrpcFuture{clientCall=ClientCallImpl{method=MethodDescriptor{fullMethodName=Request/request, type=UNARY, idempotent=false, safe=false, sampledToLocalTracing=true, requestMarshaller=com.alibaba.nacos.shaded.io.grpc.protobuf.lite.ProtoLiteUtils$MessageMarshaller@195ce0db, responseMarshaller=com.alibaba.nacos.shaded.io.grpc.protobuf.lite.ProtoLiteUtils$MessageMarshaller@2c75f128, schemaDescriptor=com.alibaba.nacos.api.grpc.auto.RequestGrpc$RequestMethodDescriptorSupplier@7668d92e}}}]]
at com.alibaba.nacos.shaded.com.google.common.util.concurrent.AbstractFuture.get(AbstractFuture.java:508) ~[nacos-client-2.2.0.jar:na]
at com.alibaba.nacos.common.remote.client.grpc.GrpcConnection.request(GrpcConnection.java:76) ~[nacos-client-2.2.0.jar:na]
... 38 common frames omitted

[KomachiSion]

超时无非3种可能：

1. 服务端负载高，请求无法及时响应， 自查是否服务端处于高CPU，线程池使用满，FullGC等问题
2. 网络问题，请求丢包或服务端回包丢失
3. 客户端负载高，请求已返回，但是客户端没有资源处理，导致积压在tcp队列中，或任务队列中，自查是否应用端处于高CPU，线程池使用满，FullGC等问题

[john1337]

超时无非3种可能：

1. 服务端负载高，请求无法及时响应， 自查是否服务端处于高CPU，线程池使用满，FullGC等问题
2. 网络问题，请求丢包或服务端回包丢失
3. 客户端负载高，请求已返回，但是客户端没有资源处理，导致积压在tcp队列中，或任务队列中，自查是否应用端处于高CPU，线程池使用满，FullGC等问题

所有的应用基本上没什么访问量，CPU、内存使用都很低，没有波峰

[KomachiSion]

如果你确认客户端服务端都没有负载，没有积压，那就是网络问题呗，丢包了