Is try catch in actors always bad practice?

I know excpetion handling in actors should in general be done with a supervisor strategy. But is this valid for all cases?

Example

There is one actor which is some kind of database.
There are several source actors which can add data to the database actor.
The parent child relationships of these actors are unknown.
To add data to the database actor the source actors must be registrated at the database actor.
If a not registrated source actors tries to add data to the database an exception is thrown.

If I follow the the error handling strategies of akka actors strictly, a supervising actor would have to handle this case.

I would prefer to catch the exception inside the database actor and send to the source actor a message, that something went wrong. Then the source actor could react (registrate to the database and try again).

Is this a good practice? Or is the total actor setup wrong? If a supervisor strategy is preferred, how should it be implemented?

Solution

It's perfectly fine to catch exceptions and make them into responses when you feel it's appropriate. I'd recommend using Scala's Try, as in:

Try(dangerousOperation()) match {
  case Success(res) => sender() ! res
  case Failure(ex)  => sender() ! UnableToStoreThingy("reasons...", ex)
}

Or something like that (you can also try.failed.map { ex => doThings(ex) }), depends on your style preference.