# Actors **URL:** https://discuss.akka.io/c/akka/actors/34.md [Latest](https://discuss.akka.io/latest.md) · [Categories](https://discuss.akka.io/categories.md) · [Tags](https://discuss.akka.io/tags.md) --- ## [About the Actors category](https://discuss.akka.io/t/about-the-actors-category/68)
**Author:** [@ktoso](https://discuss.akka.io/u/ktoso)\ **Replies:** 0
Discuss anything about Actors (including Akka Typed Actors). Use the following paragraphs for a longer description, or to establish category guidelines or rules: Why should people use this category? What is it for? … --- ## [Optional scalapb serialization binding breaks existing mapping](https://discuss.akka.io/t/optional-scalapb-serialization-binding-breaks-existing-mapping/11352)
**Author:** [@bekiroguz](https://discuss.akka.io/u/bekiroguz)\ **Replies:** 2\ **Last updated:** [March 26, 2025, 8:22am UTC](https://discuss.akka.io/t/optional-scalapb-serialization-binding-breaks-existing-mapping/11352 "2025-03-26T08:22:49Z")
Hi there, related to this feature in 2.9.0 release: feat: Optionally include serialization binding for ScalaPb by patriknw · Pull Request #32070 · akka/akka · GitHub I see that starting from akka 2.9.0, an optional ser… --- ## [Rolling Update with Remember Entites issue with newer Writer](https://discuss.akka.io/t/rolling-update-with-remember-entites-issue-with-newer-writer/11432)
**Author:** [@KDSBest](https://discuss.akka.io/u/KDSBest)\ **Replies:** 2\ **Last updated:** [May 7, 2025, 8:34am UTC](https://discuss.akka.io/t/rolling-update-with-remember-entites-issue-with-newer-writer/11432 "2025-05-07T08:34:42Z")
Hi everyone, if I perform a rolling Update with Remember-Entities on then the new node get plenty of errors from this line of code: val errMsg = s"Invalid replayed event \[sequenceNr=${r.persistent.sequenceNr}, writerUU… --- ## [Good practices for modelling double-entry Accounting domain with Actors?](https://discuss.akka.io/t/good-practices-for-modelling-double-entry-accounting-domain-with-actors/10631)
**Author:** [@olimination](https://discuss.akka.io/u/olimination)\ **Replies:** 3\ **Last updated:** [February 27, 2024, 7:29pm UTC](https://discuss.akka.io/t/good-practices-for-modelling-double-entry-accounting-domain-with-actors/10631 "2024-02-27T19:29:33Z")
Hi Akka fans! I’m a newbie to Akka and try to understand how I could model a software to handle simple transactions for a double-entry accounting system. My first thoughts: Model transactions as Actors themselves, so… --- ## [Compute fibonacci 34 fails](https://discuss.akka.io/t/compute-fibonacci-34-fails/10588)
**Author:** [@mb](https://discuss.akka.io/u/mb)\ **Replies:** 9\ **Last updated:** [January 2, 2024, 9:41pm UTC](https://discuss.akka.io/t/compute-fibonacci-34-fails/10588 "2024-01-02T21:41:36Z")
Hi For testing purposes I wrote a small program to compute fibonacci numbers the program fails (not enough memory) for fibonacci 34 fibonacci 34 creates 18454929 actors Using a common Lisp implementation of a classic… --- ## [Rethinking Message Definition in Akka Typed](https://discuss.akka.io/t/rethinking-message-definition-in-akka-typed/10505)
**Author:** [@patternstorm](https://discuss.akka.io/u/patternstorm)\ **Replies:** 1\ **Last updated:** [October 23, 2023, 6:45am UTC](https://discuss.akka.io/t/rethinking-message-definition-in-akka-typed/10505 "2023-10-23T06:45:32Z")
Introduction: Defining messages within an actor’s companion object is a prevalent practice in Akka Typed. However, a closer examination reveals that many protocols, or message interfaces, involve interactions from multi… --- ## [Akka Actor Not Receiving Self Message](https://discuss.akka.io/t/akka-actor-not-receiving-self-message/10461)
**Author:** [@joesan](https://discuss.akka.io/u/joesan)\ **Replies:** 2\ **Last updated:** [September 14, 2023, 5:46am UTC](https://discuss.akka.io/t/akka-actor-not-receiving-self-message/10461 "2023-09-14T05:46:29Z")
I have a simple implementation using fs2 where I stream at regular intervals a message that I want to send to my Actor instance, but somehow it seems not to receive the message at all. Here is my code: import cats.eff… --- ## [Akka typed actor messageAdapter bug](https://discuss.akka.io/t/akka-typed-actor-messageadapter-bug/10356)
**Author:** [@hojourner](https://discuss.akka.io/u/hojourner)\ **Replies:** 2\ **Last updated:** [June 16, 2023, 8:33am UTC](https://discuss.akka.io/t/akka-typed-actor-messageadapter-bug/10356 "2023-06-16T08:33:20Z")
Below I have a minimal repro of an issue I’m having with the messageAdapter pattern in Akka Typed. When you run it, it will print out the log messages below, which breaks the defined Message types. As far as I can tell,… --- ## [Akka dispatcher tuning cause cpu-system usage](https://discuss.akka.io/t/akka-dispatcher-tuning-cause-cpu-system-usage/10304)
**Author:** [@dennyleeGT](https://discuss.akka.io/u/dennyleeGT)\ **Replies:** 3\ **Last updated:** [May 10, 2023, 9:11pm UTC](https://discuss.akka.io/t/akka-dispatcher-tuning-cause-cpu-system-usage/10304 "2023-05-10T21:11:17Z")
Hello, akka v2.6.19 scala 2.13.10 I have an akka system running that spawns an actor to serve the request. Inside the request actor it does cpu-computation work and make several non-blocking http requests. Previousl… --- ## [Creating Guardian Actor with SpawnProtocol](https://discuss.akka.io/t/creating-guardian-actor-with-spawnprotocol/9211)
**Author:** [@AND2797](https://discuss.akka.io/u/AND2797)\ **Replies:** 4\ **Last updated:** [May 1, 2023, 7:07am UTC](https://discuss.akka.io/t/creating-guardian-actor-with-spawnprotocol/9211 "2023-05-01T07:07:10Z")
I want to create a GuardianActor with the capability of spawning actors. I’m confused how this actor should be created. Currently I’m trying to do something like this → public class GuardianActor extends AbstractBehavi… --- ## [Actor System timed-out during coordinated shutdown phase \[actor-system-terminate\]](https://discuss.akka.io/t/actor-system-timed-out-during-coordinated-shutdown-phase-actor-system-terminate/10174)
**Author:** [@VaisnavM](https://discuss.akka.io/u/VaisnavM)\ **Replies:** 0\ **Last updated:** [February 8, 2023, 10:04am UTC](https://discuss.akka.io/t/actor-system-timed-out-during-coordinated-shutdown-phase-actor-system-terminate/10174 "2023-02-08T10:04:25Z")
Currently we are working on a scenario which involves simulating a network partition in an akka cluster. While testing it, we found that the actor system in one of the nodes of the downing partition experiences time out … --- ## [Using TCP with AKKA Typed](https://discuss.akka.io/t/using-tcp-with-akka-typed/10133)
**Author:** [@haha](https://discuss.akka.io/u/haha)\ **Replies:** 2\ **Last updated:** [January 18, 2023, 11:12am UTC](https://discuss.akka.io/t/using-tcp-with-akka-typed/10133 "2023-01-18T11:12:53Z")
Hi I’m trying to create a TCP server with AKKA typed. I already got a POC working with AKKA Classic based actors, but I’m struggling with converting the full POC to AKKA typed. The current roadblock is that AKKA typed … --- ## [Getting 'LocalActorRefProvider(akka://APIX) : guardian failed, shutting down system' Error](https://discuss.akka.io/t/getting-localactorrefprovider-akka-apix-guardian-failed-shutting-down-system-error/10025)
**Author:** [@Janani](https://discuss.akka.io/u/Janani)\ **Replies:** 0\ **Last updated:** [October 15, 2022, 7:34am UTC](https://discuss.akka.io/t/getting-localactorrefprovider-akka-apix-guardian-failed-shutting-down-system-error/10025 "2022-10-15T07:34:27Z")
We are currently using akka-actor\_2.10-2.3.8, Getting the below error and we couldn’t able to find the root cause with the provided log. LocalActorRefProvider(akka://APIX) : guardian failed, shutting down system java.l… --- ## [\`forward\` pattern in Typed](https://discuss.akka.io/t/forward-pattern-in-typed/7217)
**Author:** [@ignatius](https://discuss.akka.io/u/ignatius)\ **Replies:** 5\ **Last updated:** [August 25, 2022, 4:59pm UTC](https://discuss.akka.io/t/forward-pattern-in-typed/7217 "2022-08-25T16:59:18Z")
Hi, In classic, you could have actor A ask actor B, B could forward that request to C, and C would respond to A (on B's behalf). “A” would ask with a timeout, and handle the same, but B would simply forward the request… --- ## [Integrating Guice with Typed Actors](https://discuss.akka.io/t/integrating-guice-with-typed-actors/9797)
**Author:** [@markus.guenther](https://discuss.akka.io/u/markus.guenther)\ **Replies:** 0\ **Last updated:** [June 3, 2022, 9:34am UTC](https://discuss.akka.io/t/integrating-guice-with-typed-actors/9797 "2022-06-03T09:34:20Z")
I’m currently in the process of desiging an actor hierarchy to discover things about a given cluster connection. The design is reasonably simple: there is a coordinator, which reacts on external signals and dynamically c… --- ## [MergeHub is not cleaning up in the heap area](https://discuss.akka.io/t/mergehub-is-not-cleaning-up-in-the-heap-area/9740)
**Author:** [@salitha94](https://discuss.akka.io/u/salitha94)\ **Replies:** 6\ **Last updated:** [May 29, 2022, 8:38am UTC](https://discuss.akka.io/t/mergehub-is-not-cleaning-up-in-the-heap-area/9740 "2022-05-29T08:38:40Z")
We are experiencing something weird on Akka streams implementation. When so many incoming messages are there(after creating a set of actors simultaneously), we get full GC issues. We have analyzed backend using MAT and V… --- ## [Unable to run after migration from jdk8 to jdk11](https://discuss.akka.io/t/unable-to-run-after-migration-from-jdk8-to-jdk11/9732)
**Author:** [@dbowo](https://discuss.akka.io/u/dbowo)\ **Replies:** 1\ **Last updated:** [May 4, 2022, 6:55am UTC](https://discuss.akka.io/t/unable-to-run-after-migration-from-jdk8-to-jdk11/9732 "2022-05-04T06:55:38Z")
In the process of migration from java 8 to 11, spring application failed to start with such error when creating ActorSystem The following method did not exist: scala.runtime.ScalaRunTime$.wrapRefArray We were usin… --- ## [Akka version for java 17](https://discuss.akka.io/t/akka-version-for-java-17/9695)
**Author:** [@gilh](https://discuss.akka.io/u/gilh)\ **Replies:** 5\ **Last updated:** [April 13, 2022, 10:16am UTC](https://discuss.akka.io/t/akka-version-for-java-17/9695 "2022-04-13T10:16:02Z")
What is minimal akka version that I can use, using JDK 17 for compilation and runtime ? Currently migrating our code from java 8 to java 17, and wish to upgrade major versions as little as possible. Current we are work… --- ## [Testing akka typed ask pattern](https://discuss.akka.io/t/testing-akka-typed-ask-pattern/9601)
**Author:** [@binkabir](https://discuss.akka.io/u/binkabir)\ **Replies:** 0\ **Last updated:** [March 12, 2022, 5:39pm UTC](https://discuss.akka.io/t/testing-akka-typed-ask-pattern/9601 "2022-03-12T17:39:57Z")
Hello here, Any pointers on how to test an akka typed ask pattern ? something like this aggegatorService.ask( replyTo: ActorRef\[Client.Response\] =\> GetCurrentData( clientId = 1, replyTo = replyTo) ) … --- ## [Akka Actor and Project Loom](https://discuss.akka.io/t/akka-actor-and-project-loom/9599)
**Author:** [@Fizhh](https://discuss.akka.io/u/Fizhh)\ **Replies:** 0\ **Last updated:** [March 12, 2022, 10:34am UTC](https://discuss.akka.io/t/akka-actor-and-project-loom/9599 "2022-03-12T10:34:51Z")
Hi, i am wondering about difference between Akka Actor and Virtual thread in Project Loom. Awww, each platform thread has many Actor and it also has many virtual thread. Thank you so much --- ## [Recreating actors and selecting non-existant actors](https://discuss.akka.io/t/recreating-actors-and-selecting-non-existant-actors/9569)
**Author:** [@AND2797](https://discuss.akka.io/u/AND2797)\ **Replies:** 0\ **Last updated:** [March 1, 2022, 7:34pm UTC](https://discuss.akka.io/t/recreating-actors-and-selecting-non-existant-actors/9569 "2022-03-01T19:34:21Z")
Hi I have two use cases I would like some advice on. 1.) If I stop an actor - and create an actor with the same name, what is the behavior of ActorSelection? In the documentation it says ActorSelection on the other h… --- ## [How does .withRouter(new SmallestMailboxPool()) work?](https://discuss.akka.io/t/how-does-withrouter-new-smallestmailboxpool-work/9557)
**Author:** [@AND2797](https://discuss.akka.io/u/AND2797)\ **Replies:** 3\ **Last updated:** [February 25, 2022, 4:52pm UTC](https://discuss.akka.io/t/how-does-withrouter-new-smallestmailboxpool-work/9557 "2022-02-25T16:52:06Z")
Hi, I am confused how .withRouter(new SmallestMailboxPool(size)) works. I am looking at some code where the actor is spawned like so - system.actorOf(ActorA.props(5), "ActorA") within the ActorA class public ActorA… --- ## [Actors misbehaving when service has multiple nodes](https://discuss.akka.io/t/actors-misbehaving-when-service-has-multiple-nodes/9052)
**Author:** [@salitha94](https://discuss.akka.io/u/salitha94)\ **Replies:** 3\ **Last updated:** [November 24, 2021, 1:33pm UTC](https://discuss.akka.io/t/actors-misbehaving-when-service-has-multiple-nodes/9052 "2021-11-24T13:33:42Z")
There’s a backend service that holds 2 instances on AWS. Service is communicating messages via actors. So, actors are created when the websocket request comes to the backend service. An actor can be created on instance1 … --- ## [akka.actor.Inbox gone from Akka 2.6+?](https://discuss.akka.io/t/akka-actor-inbox-gone-from-akka-2-6/7857)
**Author:** [@nomark](https://discuss.akka.io/u/nomark)\ **Replies:** 3\ **Last updated:** [October 27, 2021, 5:35pm UTC](https://discuss.akka.io/t/akka-actor-inbox-gone-from-akka-2-6/7857 "2021-10-27T17:35:00Z")
Our team was using a 2.4 version (Scala 2.11) of Akka for Java. We were tasked with upgrading this version, and when trying to go to the latest (2.6 with Scala 2.13), it looks like we’re using the akka.actor.Inbox class… --- ## [Shutting down/Stopping the BehaviorTestKit](https://discuss.akka.io/t/shutting-down-stopping-the-behaviortestkit/8892)
**Author:** [@dh10](https://discuss.akka.io/u/dh10)\ **Replies:** 0\ **Last updated:** [October 13, 2021, 8:32pm UTC](https://discuss.akka.io/t/shutting-down-stopping-the-behaviortestkit/8892 "2021-10-13T20:32:06Z")
I am currently using the BehaviorTestKit (BehaviorTestKit) to perform synchronous testing of an actor that I have created. I send the test actor I have created (using BehaviorTestKit#create) my stop message, which upon … --- ## [Spawn Global Actors Synchronously](https://discuss.akka.io/t/spawn-global-actors-synchronously/8638)
**Author:** [@ignatius](https://discuss.akka.io/u/ignatius)\ **Replies:** 1\ **Last updated:** [August 23, 2021, 6:36am UTC](https://discuss.akka.io/t/spawn-global-actors-synchronously/8638 "2021-08-23T06:36:09Z")
Hi, I’d like certain actors to be globally available in my application. My specific use-case is a “status actor” that monitors the overall health of the application, who any actor should be able to report to. I want th… --- ## [IO(Udp) SimpleSender has message size limits. What are they?](https://discuss.akka.io/t/io-udp-simplesender-has-message-size-limits-what-are-they/8553)
**Author:** [@reid-spencer](https://discuss.akka.io/u/reid-spencer)\ **Replies:** 0\ **Last updated:** [July 23, 2021, 1:18pm UTC](https://discuss.akka.io/t/io-udp-simplesender-has-message-size-limits-what-are-they/8553 "2021-07-23T13:18:02Z")
I keep getting the following debug logging from the Classic Networking IO(Udp) par of Akka. 09:11:16.029 \[eCPRISpec-classic-akka.actor.default-dispatcher-10\] DEBUG akka.io.SelectionHandler - Message too long 09:11:16.03… --- ## [Actor + Playframework](https://discuss.akka.io/t/actor-playframework/8486)
**Author:** [@Ram](https://discuss.akka.io/u/Ram)\ **Replies:** 0\ **Last updated:** [July 11, 2021, 7:01pm UTC](https://discuss.akka.io/t/actor-playframework/8486 "2021-07-11T19:01:45Z")
Hi, New to akka + play. I have a scheduler that sends a message to an Actor (using akka quartz). During scheduled time, I want to implement the following - The actor gets list of jobs. (1000s of jobs). Call it parent … --- ## [Read-only Persistent Actor](https://discuss.akka.io/t/read-only-persistent-actor/8343)
**Author:** [@ignatius](https://discuss.akka.io/u/ignatius)\ **Replies:** 4\ **Last updated:** [June 30, 2021, 2:14pm UTC](https://discuss.akka.io/t/read-only-persistent-actor/8343 "2021-06-30T14:14:09Z")
I’m thinking about the following: Say, I have a live application that collects data and represents the processed data in a persistent actor. The persistent actor’s events are written to a distributed cassandra database. … --- ## [Sharding entity custom Stop msg and HashCodeNoEnvelopeMsgExtractor](https://discuss.akka.io/t/sharding-entity-custom-stop-msg-and-hashcodenoenvelopemsgextractor/8423)
**Author:** [@pawelkaczor](https://discuss.akka.io/u/pawelkaczor)\ **Replies:** 4\ **Last updated:** [June 30, 2021, 2:07pm UTC](https://discuss.akka.io/t/sharding-entity-custom-stop-msg-and-hashcodenoenvelopemsgextractor/8423 "2021-06-30T14:07:11Z")
It seems that it is not possible to use custom Stop message together with HashCodeNoEnvelopeMessageExtractor: sealed trait Message { def mpId: String } case class Stop() extends Message { def mpId: String = thro… [Next page](https://discuss.akka.io/c/akka/actors/34.md?page=1)