akka/akka-core

"Collapsing" router or contrib pattern

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#16,323 opened on Nov 18, 2014

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 (3 comments) (0 reactions) (0 assignees)Scala (13,277 stars) (3,547 forks)batch import
1 - triagedhelp wantedt:core

Description

This is a nice pattern we could implement as either a router or example. Tomek Nurkiewicz recently blogged about how Hystrix has this built in here: http://www.nurkiewicz.com/2014/11/batching-collapsing-requests-in-hystrix.html

The pattern is about lessening the number of requests sent to an "expensive to call" resource by "collapsing" multiple calls within some time into one message to that expensive resource and then responding back to all interested parties. We can easily implement something like this, so I figured it would be a nice task to pick up if someone wants to contribute a "specialised single destination collapsing Router" like this :-)

Hystrix docs: https://github.com/Netflix/Hystrix/wiki/How-To-Use#Collapsing

Contributor guide

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.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
3-5 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Akka actor basicsCollapsing pattern (Hystrix)Akka router APIScala
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
35
Research direction
Study the existing Akka router implementations in the source code (e.g., akka routing package). Understand the Hystrix collapsing pattern as described in the linked blog post and Hystrix documentation. The issue expects a specialized single destination collapsing router that batches requests within a time window. Look at the issue comments for any additional guidance. Implement as either a router or a contrib example.