Multiple DeadLetters generated during petabridge.cmd host shutdown

[robik75]

Each time i initiate a shutdown of the actor system i get a bunch of petabridge.cmd related deadletter info log entries like this:

[11:18:30.470 INF] [akka://executor/user/petabridge.cmd] Shutting down petabridge.cmd host...
[11:18:30.476 INF] [akka://executor/system/deadLetterListener] Message SocketAsyncEventArgs from akka://executor/deadLetters to akka://executor/system/IO-TCP/$a was not delivered. 1 dead letters encountered.
[11:18:30.477 INF] [akka://executor/system/deadLetterListener] Message SocketAsyncEventArgs from akka://executor/deadLetters to akka://executor/system/IO-TCP/$a was not delivered. 2 dead letters encountered.
[11:18:30.477 INF] [akka://executor/system/deadLetterListener] Message SocketAsyncEventArgs from akka://executor/deadLetters to akka://executor/system/IO-TCP/$a was not delivered. 3 dead letters encountered.
[11:18:30.477 INF] [akka://executor/system/deadLetterListener] Message SocketAsyncEventArgs from akka://executor/deadLetters to akka://executor/system/IO-TCP/$a was not delivered. 4 dead letters encountered.
[11:18:30.478 INF] [akka://executor/system/deadLetterListener] Message SocketAsyncEventArgs from akka://executor/deadLetters to akka://executor/system/IO-TCP/$a was not delivered. 5 dead letters encountered.
[11:18:30.478 INF] [akka://executor/system/deadLetterListener] Message SocketAsyncEventArgs from akka://executor/deadLetters to akka://executor/system/IO-TCP/$a was not delivered. 6 dead letters encountered.
[11:18:30.478 INF] [akka://executor/system/deadLetterListener] Message SocketAsyncEventArgs from akka://executor/deadLetters to akka://executor/system/IO-TCP/$a was not delivered. 7 dead letters encountered.
[11:18:30.479 INF] [akka://executor/system/deadLetterListener] Message SocketAsyncEventArgs from akka://executor/deadLetters to akka://executor/system/IO-TCP/$a was not delivered. 8 dead letters encountered.
[11:18:30.479 INF] [akka://executor/system/deadLetterListener] Message SocketAsyncEventArgs from akka://executor/deadLetters to akka://executor/system/IO-TCP/$a was not delivered. 9 dead letters encountered.

Is this an expected behaviour? And how could i prevent this from happening?

[Aaronontheweb]

This is normal behavior - it's just the Akka.IO actors shutting down