akka/akka-core

Add an optional buffer/parallelism parameter for actorRefWithAck

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#26,129 opened on Dec 17, 2018

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 (6 comments) (0 reactions) (0 assignees)Scala (3,547 forks)batch import
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Description

Flow.ask currently takes in a parallelism factor as an optional parameter. This allows messages to buffer in the destination ActorRef's mailbox. E.g.,

def myFlow(ref: ActorRef) = {
  Source(1 to 100)
    .ask[Response](4)(ref) //allows 4 messages to send before waiting for a Response
    .to(Sink.ignore)
}

Sink.actorRefWithAck does not have any such functionality. Messages do not buffer.

def myAckFlow(ref: ActorRef) = {
  Source(1 to 100)
    //waits for a Response before sending the next element
    .runWith(Sink.actorRefWithAck(ref,Init,Response,Completed, ex => Error(ex))
}

Johan and I discussed this briefly, and he felt like it would be a reasonable thing to add a parallelism (or buffer) parameter to actorRefWithAck.

Contributor guide

Research direction
Implement an optional parallelism parameter for Sink.actorRefWithAck, modeled after the existing Flow.ask pattern, to allow buffering of messages to the destination ActorRef's mailbox.
Tech stack
scala
Domain
backend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Mostly clear
Prerequisites
ScalaAkka
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60