Yaroslav,
The ask pattern doesn't execute synchronously but returns a Future[Any]
immediately, which your program is ignoring. The future captures the
response from the actor at some future time (when the message send/reply is
complete). However, in your main program, that infinite loop is going to
many of those Future[Any] responses very quickly which will eventually
exhaust memory or overflow the message buffer. All those created future
objects aren't leaks per se as much as they are being created so fast that
the garbage collector has trouble keeping up with it.
If you wanted to make those calls synchronous, you should use the
Await.result idiom by changing the loop to:
while (true) {
val future = actor ? "Request"
val result = Await.result(future, timeout.duration)
assert(result == "Response")
}
Hope that helps.
Reid.
On Sunday, March 29, 2015 at 5:04:50 AM UTC-4, Yaroslav Klymko wrote:
>
> The minimal app to reproduce this:
>
> import akka.actor.{Actor, ActorSystem, Props}
> import akka.pattern.ask
> import akka.util.Timeout
> import scala.concurrent.duration._
>
> object MemoryLeakApp extends App {
> val system = ActorSystem()
> val actor = system.actorOf(Props[MyActor])
> implicit val timeout = Timeout(3.seconds)
> while (true) {
> actor ? "Request"
> }
> }
>
> class MyActor extends Actor {
> def receive = {
> case _ =>
> val actor = sender()
> context.watch(actor)
> actor ! "Response"
> }
> }
>
>
> On Sunday, March 29, 2015 at 12:03:43 PM UTC+3, Yaroslav Klymko wrote:
>>
>> Hi guys,
>> Root cause of my issue has been found, in short it is caused by *context
>> watch sender()*, where the sender is PrmiseActorRef.
>>
>>
>> On Sunday, March 29, 2015 at 10:33:47 AM UTC+3, Yaroslav Klymko wrote:
>>>
>>> So PrmiseActorRef is leaking and keeps reference on Promise &
>>> WriteEventsCompleted, still I'm not able to find a combination of
>>> dispatchers/actors to reproduce on simple example.
>>>
>>> On Saturday, March 28, 2015 at 9:33:15 PM UTC+2, Yaroslav Klymko wrote:
>>>>
>>>> Hi guys,
>>>> I have a very strange problem, it was originally spotted by @gfduszynski
>>>> https://github.com/EventStore/EventStore.Akka.Persistence/issues/11
>>>>
>>>> Here is a problematic line of code
>>>>
>>>> https://github.com/EventStore/EventStore.Akka.Persistence/blob/v2.0.0/src/main/scala/akka/persistence/eventstore/journal/EventStoreJournal.scala#L28
>>>>
>>>> Basically it is a *actor ? WriteEvents* which returns
>>>> *Future[WriteEventsCompleted]*, these *WriteEventsCompleted* messages
>>>> are leaking, however *actor ! WriteEvents *is not leaking...
>>>> Also I couldn't reproduce this using simple app without akka
>>>> persistence.
>>>>
>>>> I will really appreciate any help, any ideas.
>>>> Thanks!
>>>>
>>>>
>>>>
>>>>
>>>> <https://lh3.googleusercontent.com/-GswiQ2lLtTU/VRcAmBy7mDI/AAAAAAAAMHE/0fjbSplbpK4/s1600/Screenshot%2Bat%2BMar%2B28%2B21-26-50.png>
>>>>
>>>>
>>>>
>>>> <https://lh3.googleusercontent.com/-iBvp3mltxVs/VRcArTBLSpI/AAAAAAAAMHM/1E9raW_PKnI/s1600/Screenshot%2Bat%2BMar%2B28%2B21-26-35.png>
>>>>
>>>>
>>>>
>>>>
--
>>>>>>>>>> Read the docs: http://akka.io/docs/
>>>>>>>>>> Check the FAQ:
>>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html
>>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user
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