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Using DNS Service Discovery returns UNAVAILABLE: NameResolver returned an empty list

See original GitHub issue

What version of gRPC are you using?

1.15.1

What did you expect to see?

One of the scenarios is as follows:
- Using envoyproxy as Load balancer.
- Using AWS Service Discovery as DNS Service Discovery
- DNS Service Discovery server that serves as an A record pointing to that load balancer
- One “backend”, which the load balancer points to
- Such a flow
  - gRPC client server→ envoy proxy → AWS Service Discovery → gRPC api server
The gRPC client server will return UNAVAILABLE: NameResolver returned an empty list when the ip of envoy is changed.
It seems that gRPC client server has done DNS cache and it is not updated to new ip.

stacktrace

io.grpc.StatusRuntimeException: UNAVAILABLE: NameResolver returned an empty list
    at io.grpc.Status.asRuntimeException(Status.java:526)
    at io.grpc.stub.ClientCalls$UnaryStreamToFuture.onClose(ClientCalls.java:482)
    at io.grpc.PartialForwardingClientCallListener.onClose(PartialForwardingClientCallListener.java:39)
    at io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:23)
    at io.grpc.ForwardingClientCallListener$SimpleForwardingClientCallListener.onClose(ForwardingClientCallListener.java:40)
    at io.grpc.internal.CensusStatsModule$StatsClientInterceptor$1$1.onClose(CensusStatsModule.java:678)
    at io.grpc.PartialForwardingClientCallListener.onClose(PartialForwardingClientCallListener.java:39)
    at io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:23)
    at io.grpc.ForwardingClientCallListener$SimpleForwardingClientCallListener.onClose(ForwardingClientCallListener.java:40)
    at io.grpc.internal.CensusTracingModule$TracingClientInterceptor$1$1.onClose(CensusTracingModule.java:403)
    at io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:459)
    at io.grpc.internal.ClientCallImpl.access$300(ClientCallImpl.java:63)
    at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.close(ClientCallImpl.java:546)
    at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.access$600(ClientCallImpl.java:467)
    at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:584)
    at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
    at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

Issue Analytics

State:
Created 5 years ago
Comments:11 (7 by maintainers)

Top GitHub Comments

1reaction

louizocommented, Nov 13, 2018

@yutachaos Note that if you use it on Android platform, you have to add permission for INTERNET connection in your AndroidManifest.xml. Just before “<Application” line add : <uses-permission android:name="android.permission.INTERNET" /> and build again.

0reactions

ejona86commented, Dec 20, 2018

The reported error at this point is pretty good (as in, the best we can provide). It seems the problem is just connectivity issues between the client and host. Closing.

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