[REEF-446] When a port can't be bound, NettyMessagingTransport runs into NullPointerException

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.14
• Component/s: Wake
• Assignee: Sergey Dudoladov
• Reporter: Brian Cho
• Created: 03/Jul/15 04:28
• Updated: 06/Nov/15 16:46
• Resolved: 06/Nov/15 16:46

Description

I've run into a situation where my machine can't find a port with the default TcpPortProvider. Why it can't find a port after 1000 random tries is still beyond me. However, I do think I found a bug.

Basically, NettyMessagingTransport finishes its constructor even when the port is bound, because of the following:

        if (!ports.hasNext()) {
          break;
        }

Then, I run into a NullPointerException later on close, because the acceptor field is null.

java.lang.NullPointerException
	at org.apache.reef.wake.remote.transport.netty.NettyMessagingTransport.close(NettyMessagingTransport.java:213)
	at org.apache.reef.wake.remote.impl.DefaultRemoteManagerImplementation$1.run(DefaultRemoteManagerImplementation.java:221)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
	at java.util.concurrent.FutureTask.run(FutureTask.java:262)
	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)

Should we just raise a RuntimeException if a port can't be found? Or, is there any way to "recover" from this?