Hi Jaap,
This is located here in the documentation:
Using ask will send a message to the receiving Actor as with tell, and the
receiving actor must reply withsender() ! reply in order to complete the
returned Future with a value. The ask operation involves creating an
internal actor for handling this reply, which needs to have a timeout after
which it is destroyed in order not to leak resources; see more below.
Warning
To complete the future with an exception you need send a Failure message to
the sender. This is *not done automatically* when an actor throws an
exception while processing a message.
1. try {
2. val result = operation()
3. sender() ! result
4. } catch {
5. case e: Exception =>
6. sender() ! akka.actor.Status.Failure(e)
7. throw e
8. }
http://doc.akka.io/docs/akka/2.3.5/scala/actors.html
On Thu, Sep 4, 2014 at 1:22 PM, Jaap Taal <[email protected]> wrote:
> Let's say I have an actor that interacts with an FTP server (which is done
> by blocking code from an existing FTP lib).
>
> I have code that uses '?' like this:
>
> val response:Future[Boolean] = ftpActor ? DoesFileExist("filename")
>
> What is the best way to model a general error. I've read that using try
> catch in the actor is not the best way to do it (
> http://doc.akka.io/docs/akka/snapshot/java/howto.html#Single-Use_Actor_Trees_with_High-Level_Error_Reporting
> ).
>
> This custom supervision described in that howto is not what I'm aiming
> for. The ftpActor works 99% of the time, but for the instances that it
> doesn't, the ftpActor doesn't notify the sender of this failure.
> Examples could be an incorrectly configured username password.
> The caller of DoesFileExist receives a timeout exception which is not
> really what's going on.
>
> So what's generally the best way to have a unhappy path with such an
> actor? I really don't want to add more actors into the equation, just to
> support the unhappy flow.
>
>
> Thanks,
> Jaap
>
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--
Cheers,
√
--
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>>>>>>>>>> Check the FAQ:
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>>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user
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