Questions tagged [akka]
Akka is a toolkit and runtime for building highly concurrent, distributed, and fault tolerant event-driven applications on the JVM
Can the actor model replace a database?
After doing some research regarding the actor model, Im still not really sure what an actor actually is.. and what its supposed to "replace". From what I have understood an actor is supposed ...
Sharing akka actors on multiple backend instances
I have a web applications (angular) which is connected to backend using websockets. The role of web app is to display data from multiple sources (which are updated constantly by some Scala Spark apps) ...
Shared immutable state between actors
What are the drawbacks of sharing immutable state between actors in a non-clustered system? It's clear as to why a mutable shared state works against a lot of the guarantees that the actor model ...
Processing messages in parallel with Kafka & Akka
We have data in Kafka which we need to export to multiple destinations. Each message key is to be exported to one destination. A destination can be a REST endpoint, a file, a database etc. Each ...
RMI vs APIs vs Akka Cluster
We have a Java Play Framework Application which we want to scale out into a cluster. The only issue is that there are services ran by the Akka Scheduler once per day, and we don't want these services ...
Does Akka support communication with external threads
I have been developing with Orleans actor implementation. Recently, I saw that we were scheduling a long running job on an actor, which was effectively blocking the actor since it couldn't process the ...
Periodically update files from s3 in a Java maven library used as Packaged JAR
I have an application say x which uses another Java library(say Y) as a JAR file . So y basically needs to download a file and load it into memory before any of it's methods are called at runtime by X....
How to implement semantics of serializability in eventually consistent system?
In a distributed asynchronous system serializability cannot be achieved, but we still have to somehow provide the semantics. Consider quite natural requirement that user must have unique email or no ...
Is the actor model suited for an application dealing with elapsed time?
I need to create a distributed application with timers / periodically checking two timestamps for elapsed time. Is it possible to achieve following behaviour with the actor model: Spawn Child actor ...
How to integrate WPF and AKKA
I'm new to AKKA and i can't figure out a general proper way to integrate a backend actor system with my WPF views. I studied a few examples i found (all very similar, probably based on this), but in ...
Akka Event Sourcing - how to create Actor per Entity
I was reading Akka Persistance documentation and it says that Akka is good for Event Sourcing. Imagine I have a User entity. Each user is defined uniquely with ID and has some properties and some ...
Is the Actor Model an alternative to transactions?
I know that transactions use locks. It is claimed that actors liberate us from shared state and locks make sure all crashes are the same as clean shutdowns: this can be done through practices such ...
Akka.Net - real scenarios of usage
Now I'm trying to understand Actor model. I know main concepts like everything is an actor etc. I see a lot of words like "it's very good from performance point of view", "no locks because there is no ...
Placing case classes
If the supervisor and its child actors are sharing the same messages, which is the right place to keep those case classes? Should it be in both Supervisor and the individual actors or should it be in ...
What is the reason behing Tuples instead of HList in akka-http
As I can see in recent releases of akka-http, successor of spray, spray-routing's approach of using shapeless HList was replaced in favor of self-included Tuple What is the motivation for this ...
Architecture for Real Time data processing
I'm looking at building out the architecture for the following, and wanted to see what others think about it. Assume that the system is running some non-trivial algorithm (so it's not simply a sum ...
In Actor Pattern (AKKA.Net) Should actors be classes OR Objects?
Im Just getting started with actor pattern. Coming from UnitOfWork pattern. Lets say i want to create Actor Pattern for a Employee Management System to mark they are present or absent. The Problem Im ...
How do I design concurrent scalable system with guaranteed ordering? How about Akka?
I have designed a simple PoC system that processes a feed of prices that tick. It consumes a stream of "Ticker, Price" objects off JMS and updates a map, so that the map simply contains the latest ...
akka and futures, which ExecutionContext should be used
Following this blog by @Tomasz Nurkiewicz we can see that 4 different approaches are available for picking the ExecutionContext, when interacting with akka actors, for scala futures to run on. import ...
Why is Akka good for concurrency?
I am new to Akka and actor framework - I am sure I am missing something obvious, please accept my apologies in advance. I keep reading that one of the main points to choose Akka is the way it manages ...
Does Akka obsolesce JMS/AMQP message brokers? [closed]
I spent the last week deep diving into the Akka docs and finally understand what actor systems are, and the problems that they solve. My understanding (and experience with) traditional JMS/AMQP ...
Polyglot Node.js with Typesafe Akka for Actor Model
I have a case that needs to manipulate a large stream of JSON and inject it into Apache HBase. Our system works on Node.js with Mongo then, since we need to enhance performance, so HBase is choosen to ...
Is Erlang really an actor model language?
I was reading this article: http://www.doc.ic.ac.uk/~nd/surprise_97/journal/vol2/pjm2/ And it mentions that: ...in the actor model even an integer is represented as an actor... Wikipedia ...
Actors in a sequential protocol handshake
I am new to actors and trying to implement a very sequential protocol handshake (over websockets). This is in Scala/Akka. It goes something like this: HTTPs connection is established then upgraded ...
What is a "lifted representation"?
Just ran across this term here: http://www.codemesh.io/codemesh2014/viktor-klang "We'll demonstrate the Flow API—a lifted representation—as well as a pluggable way of transforming the lifted ...
ZeroMQ and Majordomo protocol
I am learning ZeroMQ and came across the Majordomo Protocol. I am wondering if I'm understanding this correctly, is the use case the same as.. for example.. the Microsoft Azure AppFabric service? ...
Why is Akka being marketed as reactive? Is Actor Model reactive?
As far as I understand the Actor Model and the Reactive Programming are separate concepts. Actor Model does not seem to be inherently reactive to me. However the Akka framework which is an Actor ...
Entities (DDD) when using CQRS on Akka
When using Akka, CQRS style, is still there a place for Entities? Or does everything now go to Aggregates, implemented as Actors + Value Objects. I notice that most entities are written as mutable ...
When should I use ZeroMQ and when should I use Akka?
My understanding of Akka is that it allows you to define groups of mini-threads ("Actors") and then have them communicate with each other (and do work) using events. My understanding of ZeroMQ is ...
When is it NOT good to use actors in akka/erlang?
I've been working with akka for 7-8 months now daily. When I started, I would be working on applications and notice that actors would be used basically anywhere once inside the actor system for ...
What is the difference between a Future and a Promise?
What is the difference between a Future and a promise? (In Akka and Gpars.) They look the same to me as both block and return the value of the future when get is called and a promise is to get the ...
Using akka actors with service spring beans
Do you think that using akka actors in front of transactional service beans, is a good idea ? Actors are waked up by a facade used by a client application, and actor use a message to handle right ...
How can I scale spring application context?
I'm currently working on a project that need to be dynamically scaled on demand according to the need. My question is about scaling spring context. My web application has a classical multi module ...
Error checking in actor-based paradigm
I have an existing Scala application that I am trying to refactor in order to use Akka. One of the problems I have is how to manage error-checking in actor-based applications. Usually error-checking ...