액터모델의 메일박스로 통해 전달되는 이벤트들은 다양한 DB장치를 이용해 영속화가 가능하며 상태프로그래밍을 할수 있습니다.
RDB,MongoDB,ElasticSearch등 다양한 특징을 가진 전통강호 영속장치를 이용해 각각 특화된 기능을 이용할수 있겠지만
이러한 기능을 한방에 보편적으로 이용할수 있는 장치가 없을까 조사하다 발견한 DB로 Akka를 연구하는 NetCorelabs에 변종실험 대상으로 추가하였습니다.

version: '3.8'

services:
  ravendb:
    image: ravendb/ravendb:ubuntu-latest
    container_name: ravendb
    ports:
      - "9000:8080"
    environment:
      - RAVEN_Setup_Mode=None
      - RAVEN_License_Eula_Accepted=true
    volumes:
      - ravendb_data:/ravendb/data
      - ravendb_logs:/ravendb/logs

volumes:
  ravendb_data:
  ravendb_logs:

public class Member
{
    public string Id { get; set; } // RavenDB는 기본적으로 Id를 문서 키로 사용
    public string Name { get; set; }
    public string Email { get; set; }
    public int Age { get; set; }
}

public class MemberRepository
{
    private readonly IDocumentStore _store;

    public MemberRepository(IDocumentStore store)
    {
        _store = store ?? throw new ArgumentNullException(nameof(store));
    }

    public void AddMember(Member member)
    {
        using (var session = _store.OpenSession())
        {
            session.Store(member);
            session.SaveChanges();
        }
    }

    public Member GetMemberById(string id)
    {
        using (var session = _store.OpenSession())
        {
            return session.Load<Member>(id);
        }
    }

    public void UpdateMember(Member member)
    {
        using (var session = _store.OpenSession())
        {
            var existingMember = session.Load<Member>(member.Id);
            if (existingMember != null)
            {
                existingMember.Name = member.Name;
                existingMember.Email = member.Email;
                existingMember.Age = member.Age;
                session.SaveChanges();
            }
        }
    }

    public void DeleteMember(string id)
    {
        using (var session = _store.OpenSession())
        {
            var member = session.Load<Member>(id);
            if (member != null)
            {
                session.Delete(member);
                session.SaveChanges();
            }
        }
    }
}

public class MemberRepositoryTest : TestKitXunit
{
    private readonly IDocumentStore _store;
    private readonly MemberRepository _repository;
    
    public MemberRepositoryTest(ITestOutputHelper output) : base(output)
    {
        // RavenDB 임베디드 서버 초기화
        _store = new DocumentStore
        {
            Urls = new[] { "http://localhost:9000" }, // 로컬 RavenDB URL
            Database = "net-core-labs"
        };
        _store.Initialize();

        // MemberRepository 초기화
        _repository = new MemberRepository(_store);
    }
    
    [Fact]
    public void AddMember_ShouldAddMemberSuccessfully()
    {
        // Arrange
        var member = new Member
        {
            Name = "John Doe",
            Email = "john.doe@example.com",
            Age = 30
        };

        // Act
        _repository.AddMember(member);

        // Assert
        var retrievedMember = _repository.GetMemberById(member.Id);
        Assert.NotNull(retrievedMember);
        Assert.Equal("John Doe", retrievedMember.Name);
    }

    [Fact]
    public void UpdateMember_ShouldUpdateMemberSuccessfully()
    {
        // Arrange
        var member = new Member
        {
            Name = "Jane Doe",
            Email = "jane.doe@example.com",
            Age = 25
        };
        _repository.AddMember(member);

        // Act
        member.Age = 26;
        _repository.UpdateMember(member);

        // Assert
        var updatedMember = _repository.GetMemberById(member.Id);
        Assert.NotNull(updatedMember);
        Assert.Equal(26, updatedMember.Age);
    }

    [Fact]
    public void DeleteMember_ShouldDeleteMemberSuccessfully()
    {
        // Arrange
        var member = new Member
        {
            Name = "Mark Smith",
            Email = "mark.smith@example.com",
            Age = 40
        };
        _repository.AddMember(member);

        // Act
        _repository.DeleteMember(member.Id);

        // Assert
        var deletedMember = _repository.GetMemberById(member.Id);
        Assert.Null(deletedMember);
    }
    
}

public class SalesActor: ReceivePersistentActor
{
    // The unique actor id
    public override string PersistenceId => "sales-actor";
    
    // The state that will be persisted in SNAPSHOTS
    private SalesActorState _state;
    
    public SalesActor(long expectedProfit, TaskCompletionSource<bool> taskCompletion)
    {
        _state = new SalesActorState
        {
            totalSales = 0
        }; 
        
        // Process a sale:
        Command<Sale>(saleInfo =>
        {
            if (_state.totalSales < expectedProfit)
            {
                // Persist an EVENT to RavenDB
                // ===========================
                
                // The handler function is executed after the EVENT was saved successfully
                Persist(saleInfo, _ =>
                {
                    // Update the latest state in the actor
                    _state.totalSales += saleInfo.Price;

                    ConsoleHelper.WriteToConsole(ConsoleColor.Black,
                        $"Sale was persisted. Phone brand: {saleInfo.Brand}. Price: {saleInfo.Price}");

                    // Store a SNAPSHOT every 5 sale events
                    // ====================================
                    
                    if (LastSequenceNr != 0 && LastSequenceNr % 5 == 0)
                    {
                        SaveSnapshot(_state.totalSales);
                    }
                });
            }
            else if (!taskCompletion.Task.IsCompleted)
            {
                Sender.Tell(new StopSimulate());
                
                ConsoleHelper.WriteToConsole(ConsoleColor.DarkMagenta,
                    $"Sale not persisted: " +
                    $"Total sales have already reached the expected profit of {expectedProfit}");
                
                ConsoleHelper.WriteToConsole(ConsoleColor.DarkMagenta,
                    _state.ToString());
                
                taskCompletion.TrySetResult(true);
            }
        });
        
        // Handle a SNAPSHOT success msg
        Command<SaveSnapshotSuccess>(success =>
        {
            ConsoleHelper.WriteToConsole(ConsoleColor.Blue,
                $"Snapshot saved successfully at sequence number {success.Metadata.SequenceNr}");
            
            // Optionally, delete old snapshots or events here if needed
            // DeleteMessages(success.Metadata.SequenceNr);
        });
        
        // Recover an EVENT
        Recover<Sale>(saleInfo =>
        {
            _state.totalSales += saleInfo.Price;
            
            ConsoleHelper.WriteToConsole(ConsoleColor.DarkGreen,
                $"Event was recovered. Price: {saleInfo.Price}");
        });
        
        // Recover a SNAPSHOT
        Recover<SnapshotOffer>(offer =>
        {
            var salesFromSnapshot = (long) offer.Snapshot;
            _state.totalSales = salesFromSnapshot;
            
            ConsoleHelper.WriteToConsole(ConsoleColor.DarkGreen,
                $"Snapshot was recovered. Total sales from snapshot: {salesFromSnapshot}");
        });
    }
}

public override string PersistenceId => "sales-actor";

private SalesActorState _state;

Command<Sale>(saleInfo => { ... });

Persist(saleInfo, _ =>
{
    _state.totalSales += saleInfo.Price;
    
    if (LastSequenceNr % 5 == 0) {
        SaveSnapshot(_state.totalSales);
    }
});

Sender.Tell(new StopSimulate());
taskCompletion.TrySetResult(true);

Command<SaveSnapshotSuccess>(success => {
    Console.WriteLine(...);
});

Recover<Sale>(saleInfo => {
    _state.totalSales += saleInfo.Price;
});

Recover<SnapshotOffer>(offer => {
    _state.totalSales = (long)offer.Snapshot;
});

public class SalesSimulatorActor : ReceiveActor
{
    private readonly IActorRef _salesActor;
    private ICancelable scheduler;

    public SalesSimulatorActor(IActorRef salesActor)
    {
        _salesActor = salesActor;

        // Schedule the first sale simulation immediately and then every 2 seconds:
        scheduler = Context.System.Scheduler.ScheduleTellRepeatedlyCancelable(TimeSpan.Zero, 
            TimeSpan.FromSeconds(2), Self, new StartSimulate(), Self);
        
        Receive<StartSimulate>(HandleStart);
        Receive<StopSimulate>(HandleStop);
    }

    private void HandleStart(StartSimulate message)
    {
        ConsoleHelper.WriteToConsole(ConsoleColor.Black,
            $"About to simulate a sale...");

        Random random = new Random();
        string[] products = { "Apple", "Google", "Nokia", "Xiaomi", "Huawei" };

        var randomBrand = products[random.Next(products.Length)];
        var randomPrice = random.Next(1, 6) * 100; // 100, 200, 300, 400, or 500

        var nextSale = new Sale(randomPrice, randomBrand);
        _salesActor.Tell(nextSale);
    }
    
    private void HandleStop(StopSimulate message)
    {
        scheduler.Cancel();
        ConsoleHelper.WriteToConsole(ConsoleColor.DarkRed,
            "Simulation stopped");
    }
}