Blog

Mid Year Futurespective

2018-07-24

Akkatecture has been used so far as a test bed for greenfield projects with a varying amount of success, mostly positive. There are quite a few details which we would like to iron out in our documentation before launching Akkatecture's first stable version v1.0. The main of which is a comprehensive list of options on how to deploy akkatecture which the relevant deployment strategies that may accompany those very strategies.

When we take a look at the Issues, there are two that have been rather stuck in R & D

  • Support for Jobs
  • Cluster Testing

The first issue, Support for Jobs, is an issue that has largely been un-fulfilled in the .NET Core space. The ability to store deferred tasks or commands for further processing is something that would be nice to do within your domain. Most of the time this sort of thing is delegated to external infrastructure detatched from your domain. I find this quite disheartening because you may have a business rule saying "If X happens to Y, N times, then do Z at a time T". Akkatecture supports the whole use case besides the deffered part At time T. If anyone knows how to get this working in .NET Core, please feel free to reach out to me.

The second issue is more a requirement to get Akkatecture battle tested. We want to see how performant Akkatecture is under heavy loaded clustered environments, but we are confident that the underlying akka.net implementation would be fine. We will continue to study the internals of akka.net in a clustered environment to apply ourselves there.

Keep an eye out for developments :)


Welcome

2018-05-15

Akkatecture began because I found that the lack of comprehensive cqrs and es examples for akka.net was a huge oppertunity to help others. I suspect that most akka users, are the ones on the JVM side of the fence, which shows by the higher amount of community members in that open source project. Ok... onwards onto what is Akkatecture philosophically, and why I decided to build it.

Akkatecture is set of constructs and patterns written in C# ontop of akka.net. The main goal of Akkatecture is to allow developers who are using akka.net to model their business domain within the akka.net framework with less friction. Akkatecture is built on reactive messaging & treats events as first class concept, making it highly scalable, thanks akka.net! Akkatecture focusses mainly on messaging integration patterns within your domain so that you dont have to.

Akkatecture uses the actor model as the universal primitive of concurrent computation. This means that aggregates, sagas, jobs, and other domain concepts are modelled within the actor model. Invoking or interacting with the domain is done by having these actors either react through commands (sent from outside of the aggregate boundary), or through domain events, emitted from within the domain boundary, both of which are fundamentally messages. A strong case can be made for using the actor system as a basis for designing your distributed domain, because actors in actor systems embody 3 things fundamentally:

Processing - actors can do work when requested to, the requested work can only be initiated by a message, typically in the form of a command or an event, the locality of this processing is done within the instantiation of an actor itself.

Storage - actors can store local internal state, in memory, and defer the storing of its state to a persistent store. This state is also thread safe from anything outside of the actors locality since actors process one message at a time and cannot be inspected externally.

Communication - actors can communicate with each other using a pre-defined communication protocol. Typically addressed by using location transparent actor addresses. Actors communicate with message passing and that is the only way that the outside world can communicate with the actor system. Messages being commands, or events. The actor model in computer science is a mathematical model of concurrent computation that treats "actors" as the universal primitives of concurrent computation. In response to a message that it receives, an actor can: make local decisions, create more actors, send more messages, and determine how to respond to the next message received. Actors may modify their own private state, but can only affect each other through messages (avoiding the need for any defining of critical sections, or weird mutexs).

Akka based systems have been used to drive hugely scalable and highly available systems (such as Netflix and The Guardian). Even though these companies tend to run into issues at scale on a daily basis, I still see value in modelling the business domain using actors since, with some haggling, they are quite descriptive and indicative of what actually happens in the real world.

Please have a look at our documentation, go through the basic concepts, and the walkthrough to get a good understanding of what Akkatecture looks like.

Please find me on Discord, or file GitHub a issue for any questions, guidance, or support-y stuff or just say hi👋.

Status of Akkatecture

Akkatecture is still currently in development, however most of the basic building blocks have been built out, but as of yet no v1 to speak of on NuGet.

The next plan is to work on the current core library and branch it out to support:

  • typed actor references*.
  • persisted event metadata.
  • snapshotting state.
  • scheduled jobs

*nice-to-have features, not crucial, and might be axed for first version.

Some of the issues highlighted above can be seen here. However I plan to knock these off 1 by 1 and launch the first beta by June.