Microsoft.Orleans.Persistence.DynamoDB

Microsoft Orleans Persistence for DynamoDB

Introduction

Microsoft Orleans Persistence for DynamoDB provides grain persistence for Microsoft Orleans using Amazon's DynamoDB. This allows your grains to persist their state in DynamoDB and reload it when they are reactivated.

Getting Started

To use this package, install it via NuGet:

dotnet add package Microsoft.Orleans.Persistence.DynamoDB

Example - Configuring DynamoDB Persistence

using Microsoft.Extensions.Hosting;
using Orleans.Configuration;
using Orleans.Hosting;

var builder = Host.CreateApplicationBuilder(args)
    .UseOrleans(siloBuilder =>
    {
        siloBuilder
            .UseLocalhostClustering()
            // Configure DynamoDB as grain storage
            .AddDynamoDBGrainStorage(
                name: "dynamoStore",
                configureOptions: options =>
                {
                    options.Service = "us-east-1";
                    options.TableName = "OrleansGrainState";
                    options.UseProvisionedThroughput = false;
                });
    });

// Run the host
await builder.RunAsync();

Endpoints and credentials

Service selects an AWS region or an HTTP/HTTPS endpoint URL. AccessKey and SecretKey supply explicit credentials; adding Token supplies session credentials. ProfileName selects a named AWS profile when explicit keys are omitted. These credentials apply to both regions and endpoint URLs.

The AWS SDK credential chain supplies credentials for regions and HTTPS endpoints when explicit keys and a profile are omitted. HTTP endpoints use the local-development credentials dummy and dummyKey in that case. Configure explicit credentials when a DynamoDB Local instance uses an access key to select its database.

Example - Using Grain Storage in a Grain

// Define grain state class

public class MyGrainState
{
    public string Data { get; set; }
    public int Version { get; set; }
}

// Grain implementation that uses the DynamoDB storage
public class MyGrain : Grain, IMyGrain, IGrainWithStringKey
{
    private readonly IPersistentState<MyGrainState> _state;

    public MyGrain([PersistentState("state", "dynamoStore")] IPersistentState<MyGrainState> state)
    {
        _state = state;
    }

    public async Task SetData(string data)
    {
        _state.State.Data = data;
        _state.State.Version++;
        await _state.WriteStateAsync();
    }

    public Task<string> GetData()
    {
        return Task.FromResult(_state.State.Data);
    }
}

Documentation

For more comprehensive documentation, please refer to:

• Microsoft Orleans Documentation
• Grain Persistence
• AWS SDK for .NET Documentation

Feedback & Contributing

• If you have any issues or would like to provide feedback, please open an issue on GitHub
• Join our community on Discord
• Follow the @msftorleans Twitter account for Orleans announcements
• Contributions are welcome! Please review our contribution guidelines
• This project is licensed under the MIT license