Reliable Services 基于 WCF 的通信堆栈
Reliable services 框架使服务创作者能够选择他们要用于其服务的通信堆栈。 他们可以通过从 CreateServiceReplicaListeners or CreateServiceInstanceListeners 方法返回的 ICommunicationListener 来插入所选的通信堆栈。 对于想要使用基于 Windows Communication Foundation (WCF) 的通信的服务创作者,该框架提供了基于 WCF 的通信堆栈实现。
WCF 通信侦听器
特定于 WCF 的 ICommunicationListener 实现由 Microsoft.ServiceFabric.Services.Communication.Wcf.Runtime.WcfCommunicationListener 类提供。
假设我们有 ICalculator
类型的服务协定
[ServiceContract]
public interface ICalculator
{
[OperationContract]
Task<int> Add(int value1, int value2);
}
我们可以通过下列方式在服务中创建 WCF 通信侦听器。
protected override IEnumerable<ServiceReplicaListener> CreateServiceReplicaListeners()
{
return new[] { new ServiceReplicaListener((context) =>
new WcfCommunicationListener<ICalculator>(
wcfServiceObject:this,
serviceContext:context,
//
// The name of the endpoint configured in the ServiceManifest under the Endpoints section
// that identifies the endpoint that the WCF ServiceHost should listen on.
//
endpointResourceName: "WcfServiceEndpoint",
//
// Populate the binding information that you want the service to use.
//
listenerBinding: WcfUtility.CreateTcpListenerBinding()
)
)};
}
为 WCF 通信堆栈编写客户端
为编写客户端以便使用 WCF 与服务进行通信,该框架提供了WcfClientCommunicationFactory,这是特定于 WCF 的 ClientCommunicationFactoryBase 实现。
public WcfCommunicationClientFactory(
Binding clientBinding = null,
IEnumerable<IExceptionHandler> exceptionHandlers = null,
IServicePartitionResolver servicePartitionResolver = null,
string traceId = null,
object callback = null);
可以从 WcfCommunicationClientFactory 创建的 WcfCommunicationClient 访问 WCF 通信通道。
public class WcfCommunicationClient : ServicePartitionClient<WcfCommunicationClient<ICalculator>>
{
public WcfCommunicationClient(ICommunicationClientFactory<WcfCommunicationClient<ICalculator>> communicationClientFactory, Uri serviceUri, ServicePartitionKey partitionKey = null, TargetReplicaSelector targetReplicaSelector = TargetReplicaSelector.Default, string listenerName = null, OperationRetrySettings retrySettings = null)
: base(communicationClientFactory, serviceUri, partitionKey, targetReplicaSelector, listenerName, retrySettings)
{
}
}
客户端代码可以使用 WcfCommunicationClientFactory 以及用于实现 ServicePartitionClient 的 WcfCommunicationClient 来确定服务终结点,并与服务通信。
// Create binding
Binding binding = WcfUtility.CreateTcpClientBinding();
// Create a partition resolver
IServicePartitionResolver partitionResolver = ServicePartitionResolver.GetDefault();
// create a WcfCommunicationClientFactory object.
var wcfClientFactory = new WcfCommunicationClientFactory<ICalculator>
(clientBinding: binding, servicePartitionResolver: partitionResolver);
//
// Create a client for communicating with the ICalculator service that has been created with the
// Singleton partition scheme.
//
var calculatorServiceCommunicationClient = new WcfCommunicationClient(
wcfClientFactory,
ServiceUri,
ServicePartitionKey.Singleton);
//
// Call the service to perform the operation.
//
var result = calculatorServiceCommunicationClient.InvokeWithRetryAsync(
client => client.Channel.Add(2, 3)).Result;
注意
默认 ServicePartitionResolver 假设客户端正在与服务相同的群集中运行。 如果不是这样,请创建 ServicePartitionResolver 对象,并传入群集连接终结点。