service-fabric-reliable-actors-backup-and-restore.md

title	description	ms.topic	ms.author	author	ms.service	services	ms.date
Back up and restore Azure Service Fabric actors	Learn how to implement back up and restore in your Azure Service Fabric actors.	how-to	tomcassidy	tomvcassidy	service-fabric	service-fabric	07/11/2022

Implement Reliable Actors back up and restore

Note

Microsoft recommends to use Periodic back up and restore for configuring data backup of Reliable Stateful services and Reliable Actors.

In the following example, a custom actor service exposes a method to back up actor data by taking advantage of the remoting listener already present in ActorService:

public interface IMyActorService : IService
{
    Task BackupActorsAsync();
}

class MyActorService : ActorService, IMyActorService
{
    public MyActorService(StatefulServiceContext context, ActorTypeInformation typeInfo, Func<ActorBase> newActor)
        : base(context, typeInfo, newActor)
    { }

    public Task BackupActorsAsync()
    {
        return this.BackupAsync(new BackupDescription(PerformBackupAsync));
    }

    private async Task<bool> PerformBackupAsync(BackupInfo backupInfo, CancellationToken cancellationToken)
    {
        try
        {
           // store the contents of backupInfo.Directory
           return true;
        }
        finally
        {
           Directory.Delete(backupInfo.Directory, recursive: true);
        }
    }
}

public interface MyActorService extends Service
{
    CompletableFuture<?> backupActorsAsync();
}

class MyActorServiceImpl extends ActorService implements MyActorService
{
    public MyActorService(StatefulServiceContext context, ActorTypeInformation typeInfo, Func<FabricActorService, ActorId, ActorBase> newActor)
    {
       super(context, typeInfo, newActor);
    }

    public CompletableFuture backupActorsAsync()
    {
        return this.backupAsync(new BackupDescription((backupInfo, cancellationToken) -> performBackupAsync(backupInfo, cancellationToken)));
    }

    private CompletableFuture<Boolean> performBackupAsync(BackupInfo backupInfo, CancellationToken cancellationToken)
    {
        try
        {
           // store the contents of backupInfo.Directory
           return true;
        }
        finally
        {
           deleteDirectory(backupInfo.Directory)
        }
    }

    void deleteDirectory(File file) {
        File[] contents = file.listFiles();
        if (contents != null) {
            for (File f : contents) {
               deleteDirectory(f);
             }
        }
        file.delete();
    }
}

In this example, IMyActorService is a remoting contract that implements IService (C#) and Service (Java), and is then implemented by MyActorService. By adding this remoting contract, methods on IMyActorService are now also available to a client by creating a remoting proxy via ActorServiceProxy:

IMyActorService myActorServiceProxy = ActorServiceProxy.Create<IMyActorService>(
    new Uri("fabric:/MyApp/MyService"), ActorId.CreateRandom());

await myActorServiceProxy.BackupActorsAsync();

MyActorService myActorServiceProxy = ActorServiceProxy.create(MyActorService.class,
    new URI("fabric:/MyApp/MyService"), actorId);

myActorServiceProxy.backupActorsAsync();

For more information on Reliable Actors, read the following articles:

• Actor state management
• Actor lifecycle and garbage collection
• Actors API reference documentation
• .NET sample code
• Java sample code