[FLINK-5745] [network] Set uncaught exception handler for Netty threads

This sets a JVM-terminating handler that logs errors from uncaught exceptions
and terminates the process so that critical exceptions are not accidentally
lost and leave the system running in an inconsistent state.

This closes apache#3293.

flink-runtime/src/main/java/org/apache/flink/runtime/io/network/netty/NettyServer.java

@@ -30,6 +30,7 @@
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioServerSocketChannel;
 import io.netty.handler.ssl.SslHandler;
+import org.apache.flink.runtime.util.FatalExitExceptionHandler;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -44,7 +45,10 @@
 
 class NettyServer {
 
- private static final ThreadFactoryBuilder THREAD_FACTORY_BUILDER = new ThreadFactoryBuilder().setDaemon(true);
+ private static final ThreadFactoryBuilder THREAD_FACTORY_BUILDER =
+ new ThreadFactoryBuilder()
+ .setDaemon(true)
+ .setUncaughtExceptionHandler(FatalExitExceptionHandler.INSTANCE);
 
  private static final Logger LOG = LoggerFactory.getLogger(NettyServer.class);