Exmples from gRPC is not working - protocol-buffers

Question

I'm trying to run route example but when client starts to connecting to server (blockingStub.getFeature(request)) it hangs. If I stops client (ctrl+c in terminal) error occurs (look below).
Does anybody knows what might be wrong?
Stack trace:
Terminal1-server:
./gradlew routeGuideServer
:grpc-core:compileJava UP-TO-DATE
:grpc-core:animalSniffer
...
May 06, 2015 4:56:06 PM io.grpc.examples.routeguide.RouteGuideServer start
INFO: Server started, listening on 8980
// server is started; now running client
Terminal2-client:
./gradlew routeGuideClient
:grpc-core:compileJava UP-TO-DATE
:grpc-core:animalSniffer
...
:grpc-examples:classes UP-TO-DATE
May 06, 2015 4:56:51 PM io.grpc.examples.routeguide.RouteGuideClient info
INFO: *** GetFeature: lat=409,146,138 lon=-746,188,906
// at this point everythings hangs
stoping client with CTRL+C results int error in server
May 06, 2015 4:57:50 PM io.netty.channel.DefaultChannelPipeline$TailContext exceptionCaught
WARNING: An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception.
java.io.IOException: An existing connection was forcibly closed by the remote host
at sun.nio.ch.SocketDispatcher.read0(Native Method)
at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:43)
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
at sun.nio.ch.IOUtil.read(IOUtil.java:192)
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:379)
at io.netty.buffer.PooledUnsafeDirectByteBuf.setBytes(PooledUnsafeDirectByteBuf.java:311)
at io.netty.buffer.AbstractByteBuf.writeBytes(AbstractByteBuf.java:854)
at io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:242)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:115)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:510)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:467)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:381)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:353)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:703)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)

Answer 1

It is likely a bug; although the client does do some sleeps, there is no reason it should hang. I can't reproduce the problem though.
The exception on the server-side may be related, since generally the client would do a graceful shutdown which would not produce that exception. However, if a client did ungracefully shut down the connection, then you would get that warning.
I did see what I assume is your message yesterday on grpc-io#googlegroups.com, but hadn't had a chance to respond. I've created an issue for tracking the bug.