[akka-user] Re: Passivate
Ashley, perhaps this might be useful for you.
import scala.concurrent.duration._
import akka.actor._
import benefits.configuration.Settings
/* Message used by `Child` to signal `Parent` it should
* be passivated by way of PoisonPill after a configurable
* idle time.
* */
case object Passivate
trait Parent extends Actor with Stash with ActorLogging {
import Parent._
import context._
private val settings =
Settings(system).Support.Passivation
def withPassivation(receive: Receive): Receive =
receive orElse passivation
private[support] def passivation: Receive = {
case Passivate ⇒ passivate(sender())
case Terminated(ref) ⇒ logUnexpected(ref)
case WaitTick(ref) ⇒ // no-op
}
private def passivate(entry: ActorRef) = {
log.debug(sPassivation start: $entry)
watch(entry)
entry ! PoisonPill
val tick = scheduleTick(entry)
val await = awaiting(entry, tick)
become(await, discardOld = false)
}
private def awaiting(ref: ActorRef, tick: Cancellable): Receive = {
case Terminated(`ref`) ⇒ terminated(ref, tick)
case WaitTick(`ref`) ⇒ waitTick(ref)
case _ ⇒ stash()
}
private def terminated(ref: ActorRef, tick: Cancellable) = {
tick.cancel()
previousBehavior(ref)
log.debug(sPassivation end: $ref)
}
private def waitTick(ref: ActorRef) = {
previousBehavior(ref)
log.warning(sGiving up waiting for Terminated($ref))
}
private def previousBehavior(ref: ActorRef) = {
unwatch(ref)
unbecome()
unstashAll()
}
private def logUnexpected(ref: ActorRef) =
log.warning(sUnexpected terminated for $ref)
private def scheduleTick(entry: ActorRef) = {
system.scheduler.scheduleOnce(
waitTime, self, WaitTick(entry)
)
}
def waitTime: FiniteDuration =
settings.parentWaitTime
}
object Parent {
private[support] case class WaitTick(
entry: ActorRef
)
}
trait Child extends Actor with ActorLogging {
import Child._
import context._
private val settings =
Settings(system).Support.Passivation
override def preStart() = {
super.preStart()
self ! StartTimingOut
}
def passivator: ActorRef = parent
def withPassivation(receive: Receive): Receive =
receive orElse passivation
private[support] def passivation: Receive = {
case ReceiveTimeout ⇒ issuePassivate()
case StartTimingOut ⇒ startTimeout()
}
private def startTimeout() = {
log.debug(sSetting receive timeout to $idleTime)
setReceiveTimeout(idleTime)
}
private def issuePassivate() = {
log.debug(sSending Passivate to $passivator)
setReceiveTimeout(Duration.Inf)
passivator ! Passivate
}
def idleTime: FiniteDuration =
settings.childIdleTime
}
object Child {
private[support] case object StartTimingOut
}
On Wednesday, July 16, 2014 4:00:44 AM UTC+1, Ashley Aitken wrote:
Thank you Michael and Konrad for your posts.
I was somewhat confused as to whether the manager was something special or
it referred to a processors' usual supervisor / parent.
I also thought passivate was a part of akka-persistence but Konrad's post
makes it clear it is a part of cluster sharding (no wonder I couldn't find
anything about it in the docs for akka-persistence) and the Manager in
Patrik's post is a part of the cluster sharding infrastructure.
Cheers,
Ashley.
--
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[akka-user] Re: Passivate
Hello Ashey, I guess you answered your question(s) yourself: - in-between receiving Passivate and Terminated the Manager will buffer all incoming messages for the passivating Aggregate - when receiving Terminated it will flush the buffer for the Aggregate, which can result in activation again. So, the answer to both questions is yes, but the buffer for passivated actors is limited, if the limit is reached all messages will go to DeadLetters. hth, michael On Monday, 14 July 2014 17:28:42 UTC+2, Ashley Aitken wrote: A couple of quick questions about passivate and PersistentActors: Can other actors still send messages to persistent actors that have been passivated? Will these messages cause the persistent actor to be reactivated? I am asking about this in single node and clustered context. I saw elsewhere that Patrik has written this in the cluster/sharding context: - all messages are sent via the Manager actor, which creates child Aggregate instances on demand - when receiving a message the Manager extract the Aggregate identifier from the message - the Manager creates a new child Aggregate actor if it doesn't exist, and then forwards the message to the Aggregate - the Aggregate can passivate itself by sending a Passivate message to the parent Manager, which then sends PoisonPill to the Aggregate - in-between receiving Passivate and Terminated the Manager will buffer all incoming messages for the passivating Aggregate - when receiving Terminated it will flush the buffer for the Aggregate, which can result in activation again The PoisonPill can be replaced with some other custom stop message if the Aggregate needs to do further interactions with other actors before stopping. Thanks in advance for any answers. Cheers, Ashley. -- 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 --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
Re: [akka-user] Re: Passivate
Just like Michael (quoting Patrik) said :-) Also, please note that Passivate is *not *a feature of akka-persistence, it's a feature of cluster sharding: http://doc.akka.io/docs/akka/2.3.4/contrib/cluster-sharding.html It's true however that it (and the entire cluster sharding) plays very well with persistence :-) On Tue, Jul 15, 2014 at 9:19 AM, delasoul michael.ham...@gmx.at wrote: Hello Ashey, I guess you answered your question(s) yourself: - in-between receiving Passivate and Terminated the Manager will buffer all incoming messages for the passivating Aggregate - when receiving Terminated it will flush the buffer for the Aggregate, which can result in activation again. So, the answer to both questions is yes, but the buffer for passivated actors is limited, if the limit is reached all messages will go to DeadLetters. hth, michael On Monday, 14 July 2014 17:28:42 UTC+2, Ashley Aitken wrote: A couple of quick questions about passivate and PersistentActors: Can other actors still send messages to persistent actors that have been passivated? Will these messages cause the persistent actor to be reactivated? I am asking about this in single node and clustered context. I saw elsewhere that Patrik has written this in the cluster/sharding context: - all messages are sent via the Manager actor, which creates child Aggregate instances on demand - when receiving a message the Manager extract the Aggregate identifier from the message - the Manager creates a new child Aggregate actor if it doesn't exist, and then forwards the message to the Aggregate - the Aggregate can passivate itself by sending a Passivate message to the parent Manager, which then sends PoisonPill to the Aggregate - in-between receiving Passivate and Terminated the Manager will buffer all incoming messages for the passivating Aggregate - when receiving Terminated it will flush the buffer for the Aggregate, which can result in activation again The PoisonPill can be replaced with some other custom stop message if the Aggregate needs to do further interactions with other actors before stopping. Thanks in advance for any answers. Cheers, Ashley. -- 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 --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout. -- Cheers, Konrad 'ktoso' Malawski hAkker @ Typesafe http://typesafe.com -- 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 --- You received this message because you are subscribed to the Google Groups Akka User List group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
