java 5.x官方快速开始代码为什么还要连broker的地址，不是只连proxy吗

[glpcf]

Exception raised from stream response observer, clientId=##########@a5zlvzm8ps, endpoints=ipv4:172.18.0.4:8081
org.apache.rocketmq.shaded.io.grpc.StatusRuntimeException: UNAVAILABLE: io exception
at org.apache.rocketmq.shaded.io.grpc.Status.asRuntimeException(Status.java:539)
at org.apache.rocketmq.shaded.io.grpc.stub.ClientCalls$StreamObserverToCallListenerAdapter.onClose(ClientCalls.java:487)
at org.apache.rocketmq.shaded.io.grpc.PartialForwardingClientCallListener.onClose(PartialForwardingClientCallListener.java:39)
at org.apache.rocketmq.shaded.io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:23)
at org.apache.rocketmq.shaded.io.grpc.ForwardingClientCallListener$SimpleForwardingClientCallListener.onClose(ForwardingClientCallListener.java:40)
at org.apache.rocketmq.shaded.io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:563)
at org.apache.rocketmq.shaded.io.grpc.internal.ClientCallImpl.access$300(ClientCallImpl.java:70)
at org.apache.rocketmq.shaded.io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:744)
at org.apache.rocketmq.shaded.io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:723)
at org.apache.rocketmq.shaded.io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
at org.apache.rocketmq.shaded.io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:133)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:835)
Caused by: org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.channel.ConnectTimeoutException: connection timed out: /172.18.0.4:8081
at org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe$1.run(AbstractNioChannel.java:261)
at org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.util.concurrent.PromiseTask.runTask(PromiseTask.java:98)
at org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:153)
at org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.util.concurrent.AbstractEventExecutor.runTask(AbstractEventExecutor.java:174)
at org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:167)
at org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:470)
at org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:503)
at org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
at org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at org.apache.rocketmq.shaded.io.grpc.netty.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
... 1 common frames omitted

[glpcf]

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