Azure Service Fabric：使用无状态服务将数据存储到有状态服务（C＃编程）

Question

Objective: Want to create a product with some entities in a stateless service and the created product should get stored in a stateful service ( IReliableDictionary )

// Task done: I am working with Azure Service Fabric. Firstly, I created a 
// stateful service which does the job of AddProduct and GetAllProducts and the 
// data is stored in IReliableDictionary. For this I have declared, and passed 
// the object in a constructor.

private readonly IReliableStateManager _stateManager;
public ServiceFabricRepository(IReliableStateManager stateManager)
{
   _stateManager = stateManager;
}

If I am adding a product within a stateful service the product is being added into the database ( IReliableDictionary ). This is tested and its working.

The next task, what I did is add a new service ( stateless ) in the solution. The stateless should create a product with some entities ( Id , Name ). The product created should be added in my database ( stateful service)

Problem: I am able to create the product with some entities but the product is not being added in my database, because it is asking me to create an instance of IReliableStateManager in the stateless service and the stateManager is always null .

How to create an instance of IReliableStateManager in a stateless service since IReliableStateManager is provided by the stateful service inheritance hierarchy. I am creating an instance of my repository in a stateless service

//(stateManager is never assigned to and will always have its dafult value null) 
private static IReliableStateManager stateManager; 
private ServiceFabricRepository = new ServiceFabricRepository(stateManager)

I have done some search and found out that stateful service is used for data storage( Example interfaces: AddProduct or GetProduct ) and stateless Web Api is used to expose the interfaces of stateful service using service remoting or Http for communication between the services. But was unable to find any example for my scenario.

Will be very helpful for any help or suggestions

Thanks & Regards

Answer 1

You do not use IReliableStateManager directly in Stateless service, rather call Stateful service from Stateless and pass object needs to be saved.

For example: Create service proxy of stateful service in stateless service and call its method:

IProductService = ServiceProxy.Create<IProductService>(new Uri("fabric:/SfSample/ProductService"), new ServicePartitionKey(0));
var newProduct = new Product()
{
    Name = product.Name,
    Id = product.Id
};
await _productService.AddProduct(newProduct);

And Stateful service:

public class ProductService : StatefulService, IProductService
    {

        public async Task AddProduct(Product product)
        {
            var products = await StateManager.GetOrAddAsync<IReliableDictionary<Guid, Product>>("products");

            using (var tx = StateManager.CreateTransaction())
            {
                await products.AddOrUpdateAsync(tx, product.Id, product, (id, value) => product);

                await tx.CommitAsync();
            }
        }
...........
}