akka-hosting-actor-patterns

1# Akka.Hosting Actor Patterns
2 
3## When to Use This Skill
4 
5Use this skill when:
6- Building entity actors that represent domain objects (users, orders, invoices, etc.)
7- Need actors that work in both unit tests (no clustering) and production (cluster sharding)
8- Setting up scheduled tasks with akka-reminders
9- Registering actors with Akka.Hosting extension methods
10- Creating reusable actor configuration patterns
11 
12## Core Principles
13 
141. **Execution Mode Abstraction** - Same actor code runs locally (tests) or clustered (production)
152. **GenericChildPerEntityParent for Local** - Mimics sharding semantics without cluster overhead
163. **Message Extractors for Routing** - Reuse Akka.Cluster.Sharding's IMessageExtractor interface
174. **Akka.Hosting Extension Methods** - Fluent configuration that composes well
185. **ITimeProvider for Testability** - Use ActorSystem.Scheduler instead of DateTime.Now
19 
20## Execution Modes
21 
22Define an enum to control actor behavior:
23 
24```csharp
25/// <summary>
26/// Determines how Akka.NET should be configured
27/// </summary>
28public enum AkkaExecutionMode
29{
30    /// <summary>
31    /// Pure local actor system - no remoting, no clustering.
32    /// Use GenericChildPerEntityParent instead of ShardRegion.
33    /// Ideal for unit tests and simple scenarios.
34    /// </summary>
35    LocalTest,
36 
37    /// <summary>
38    /// Full clustering with ShardRegion.
39    /// Use for integration testing and production.
40    /// </summary>
41    Clustered
42}
43```
44 
45## GenericChildPerEntityParent
46…