Service Invocation

Service Invocation is a Dapr building block that enables you to call methods on microservices using HTTP or gRPC protocols. Dapr handles service discovery, routing, and secure communication between services.

Key Features

• Supports HTTP and gRPC protocols
• Built-in service discovery using Dapr sidecars
• Secure communication with mutual TLS
• Automatic retries and error handling

Example Usage

C#

// Call a method on another service using Dapr client
var client = new DaprClientBuilder().Build();
var result = await client.InvokeMethodAsync<string>("order-service", "createOrder", orderData);

Java

// Call a method on another service using Dapr client
DaprClient client = new DaprClientBuilder().build();
String result = client.invokeMethod("order-service", "createOrder", orderData, String.class).block();

Python

# Call a method on another service using Dapr client
from dapr.clients import DaprClient
with DaprClient() as client:
    resp = client.invoke_method('order-service', 'createOrder', data=order_data)

Real-World Application

You use Service Invocation to connect microservices in a distributed system. For example, an API gateway can call backend services for order processing, inventory, or billing. Dapr ensures requests are routed securely and reliably.

Related Links

• Dapr Service Invocation documentation
• Dapr SDKs