Blockchain - Virtual box is set up and error while executing Hyperledger example from github

Question

 While trying out the sample example from  https://github.com/ksachdeva/hyperledger-fabric-example I got the following error:

$ ./Example/bin/Example Hello world! starting [Ljava.lang.String;@3feba861 

Mar 15, 2018 6:27:13 PM example.Example main INFO: starting 

Mar 15, 2018 6:27:14 PM io.grpc.internal.TransportSet$1 call INFO: Created transport io.grpc.netty.NettyClientTransport@5e639e5d(/127.0.0.1:7051) for /127.0.0.1:7051 

Mar 15, 2018 6:27:15 PM io.grpc.internal.TransportSet$TransportListener transportShutdown INFO: Transport io.grpc.netty.NettyClientTransport@5e639e5d(/127.0.0.1:7051) for /127.0.0.1:7051 is being shutdown 

Mar 15, 2018 6:27:15 PM io.grpc.internal.TransportSet$TransportListener transportTerminated INFO: Transport io.grpc.netty.NettyClientTransport@5e639e5d(/127.0.0.1:7051) for /127.0.0.1:7051 is terminated 

Mar 15, 2018 6:27:15 PM io.netty.handler.codec.http2.Http2ConnectionHandler processGoAwayWriteResult WARNING: [id: 0x41d45f4a] Sending GOAWAY failed: lastStreamId '0', errorCode '2', debugData 'Connection refused: /127.0.0.1:7051'. Forcing shutdown of the connection. java.nio.channels.ClosedChannelException

Mar 15, 2018 6:27:15 PM org.hyperledger.java.shim.ChaincodeBase$1 onError SEVERE: Unable to connect to peer server: UNAVAILABLE: Transport closed for unknown reason

Can anyone help me out on this?

Answer 1

The challenge you are facing is mostly because of TLS communication error between grpc-java client to golang server.  

I think it was a problem with the handshake failing because of the version mismatch between different components. I had used a specific version of the grpc and protobuf to make it work. You can take a look at this commit hyperledger/fabric@d39194c

The "Broken pipe" could be ignored. The transport was being disconnected for other reasons. Based on the code linked, it appears overrideAuthority() was necessary, which makes sense and is "normal" in many situations. Doesn't seem there is any bug here.