MailBiz.Orleans.EventSourcing 9.3.0

.NET 9.0 This package targets .NET 9.0. The package is compatible with this framework or higher. 
dotnet add package MailBiz.Orleans.EventSourcing --version 9.3.0
                    


                    

                
NuGet\Install-Package MailBiz.Orleans.EventSourcing -Version 9.3.0
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="MailBiz.Orleans.EventSourcing" Version="9.3.0" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="MailBiz.Orleans.EventSourcing" Version="9.3.0" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="MailBiz.Orleans.EventSourcing" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add MailBiz.Orleans.EventSourcing --version 9.3.0
                    


                    

                
#r "nuget: MailBiz.Orleans.EventSourcing, 9.3.0"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
#:package MailBiz.Orleans.EventSourcing@9.3.0
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package. 
#addin nuget:?package=MailBiz.Orleans.EventSourcing&version=9.3.0
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=MailBiz.Orleans.EventSourcing&version=9.3.0
                    


                            Install as a Cake Tool

Microsoft Orleans Event Sourcing

Introduction

Microsoft Orleans Event Sourcing provides support for implementing event-sourced grains. Event sourcing is a pattern where state changes are recorded as a sequence of events rather than just storing the current state. This provides a complete history of changes and allows for powerful capabilities like replaying events, temporal querying, and more robust auditing.

Getting Started

To use this package, install it via NuGet:

dotnet add package Microsoft.Orleans.EventSourcing

Example - Creating an Event-Sourced Grain

using Orleans;
using Orleans.EventSourcing;
using System;
using System.Threading.Tasks;
using System.Collections.Generic;
using System.Linq;

// Define grain state and events
namespace BankAccount;

public class BankAccountState
{
    public decimal Balance { get; set; }
    public string AccountHolder { get; set; }
    public int Version { get; set; }
}

public class DepositEvent
{
    public decimal Amount { get; set; }
}

public class WithdrawalEvent
{
    public decimal Amount { get; set; }
}

// Grain interface
public interface IBankAccountGrain : IGrainWithStringKey
{
    Task<decimal> GetBalance();
    Task Deposit(decimal amount);
    Task Withdraw(decimal amount);
    Task<IReadOnlyList<object>> GetHistory();
}

// Event-sourced grain implementation using JournaledGrain
public class BankAccountGrain : JournaledGrain<BankAccountState, object>, IBankAccountGrain
{
    public async Task<decimal> GetBalance()
    {
        // The state is automatically hydrated from the event log
        return State.Balance;
    }

    public async Task Deposit(decimal amount)
    {
        if (amount <= 0)
            throw new ArgumentException("Deposit amount must be positive");

        // Record the event - this will be persisted and applied to state
        RaiseEvent(new DepositEvent { Amount = amount });
        
        // Confirm the event is persisted
        await ConfirmEvents();
    }

    public async Task Withdraw(decimal amount)
    {
        if (amount <= 0)
            throw new ArgumentException("Withdrawal amount must be positive");
            
        if (State.Balance < amount)
            throw new InvalidOperationException("Insufficient funds");

        // Record the event
        RaiseEvent(new WithdrawalEvent { Amount = amount });
        
        // Confirm the event is persisted
        await ConfirmEvents();
    }

    public Task<IReadOnlyList<object>> GetHistory()
    {
        // Return the complete history of events
        return Task.FromResult<IReadOnlyList<object>>(RetrieveConfirmedEvents(0, Version).ToList());
    }

    // Event handlers to update the state based on events
    protected override void ApplyEvent(object @event)
    {
        switch (@event)
        {
            case DepositEvent deposit:
                State.Balance += deposit.Amount;
                break;
                
            case WithdrawalEvent withdrawal:
                State.Balance -= withdrawal.Amount;
                break;
        }
    }
}

Example - Configuring Event Sourcing with Storage

using Microsoft.Extensions.Hosting;
using Orleans.Configuration;
using Orleans.Hosting;
using Orleans.EventSourcing;
using Microsoft.Extensions.DependencyInjection;
using System;
using System.Threading.Tasks;

var builder = Host.CreateApplicationBuilder(args)
    .UseOrleans(siloBuilder =>
    {
        siloBuilder
            .UseLocalhostClustering()
            // Configure the log consistency provider for event sourcing
            .AddLogStorageBasedLogConsistencyProvider("LogStorage")
            // Configure a storage provider to store the events
            .AddMemoryGrainStorage("PubSubStore")
            .ConfigureServices(services =>
            {
                // Configure default log consistency provider
                services.Configure<JournaledGrainOptions>(options =>
                {
                    options.DefaultLogConsistencyProvider = "LogStorage";
                });
            });
    });

var host = builder.Build();
await host.StartAsync();

// Get a reference to a grain and call it
var client = host.Services.GetRequiredService<IClusterClient>();
var bankAccount = client.GetGrain<IBankAccountGrain>("account-123");

// Call grain methods
await bankAccount.Deposit(100);
await bankAccount.Withdraw(25);
var balance = await bankAccount.GetBalance();

// Print the result
Console.WriteLine($"Account balance: ${balance}");

var history = await bankAccount.GetHistory();
Console.WriteLine($"Transaction history: {history.Count} events");

// Keep the host running until the application is shut down
await host.WaitForShutdownAsync();

Documentation

For more comprehensive documentation, please refer to:

Feedback & Contributing

Product Compatible and additional computed target framework versions.
.NET net9.0 is compatible.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed.  net10.0 was computed.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
9.3.0 313 11/17/2025