Core Concepts

Application Service

An application service is a C# interface annotated with [ServiceRoute]. It defines the public contract of a microservice — the methods available to other services and external HTTP clients. In Silky, an application service is analogous to a Controller in MVC.

Naming convention: IXxxxAppService (interface), XxxxAppService (implementation).

Service Entry

A service entry is generated for every method defined on an application service interface. It is analogous to an Action in MVC. Each service entry has:

• A unique Service Entry ID for RPC routing
• An optional WebAPI endpoint (HTTP route + verb) for external access
• Configurable governance parameters (timeout, retry, circuit breaker, etc.)

Service Entry ID

The unique identifier for a service entry, generated as:

FullyQualifiedMethodName + ParameterNames + _ + HttpVerb

Example: Demo.Contracts.IOrderAppService.GetAsync.id_Get

RPC (Remote Procedure Call)

Silky uses DotNetty TCP-based binary RPC for inter-service communication. The interface proxy pattern makes remote calls look identical to local method calls.

Dynamic Proxy

Generated at runtime via Autofac dynamic proxy (Autofac.Extras.DynamicProxy). When you inject a remote service interface, Silky provides a proxy that transparently routes the call to the correct remote instance.

Service Governance

A set of policies applied to service-to-service calls to ensure reliability and performance:

• Load Balancing: Distributes requests across healthy instances
• Circuit Breaking: Prevents cascading failures by fast-failing unhealthy routes
• Retry / Failover: Retries on infrastructure errors
• Timeout: Caps maximum wait time for a response
• Rate Limiting: Caps concurrent requests per instance

Registry Center

A service registry (Zookeeper / Nacos / Consul) that stores service metadata and endpoint addresses. Service providers register with the registry at startup; consumers query it to discover available instances.

Service Metadata

Data registered by a service provider in the registry center, including:

• hostName: Provider host name
• services: Application service definitions and their service entries
• endpoints: Network addresses of the running instance
• timeStamp: Last update time

RPC Context (RpcContext)

A request-scoped dictionary of metadata propagated through the entire call chain (HTTP → Gateway → Service A → Service B → ...). Contains user identity, TraceId, tenant ID, and custom attachments.

TCC (Try-Confirm-Cancel)

A distributed transaction pattern where each participant exposes three methods:

• Try: Reserve resources without committing
• Confirm: Commit using the reserved resources
• Cancel: Release reserved resources on failure

Module (SilkyModule)

The basic unit of framework extensibility. Each module encapsulates a cohesive set of services and configuration. Modules declare their dependencies via [DependsOn], and the framework initializes them in topological order.

Host Types

Fallback

A degraded implementation of a service interface, activated automatically when the normal RPC call fails (circuit open, timeout, etc.).

Cache Interception

An AOP-based mechanism that checks the distributed cache before executing an RPC call. On a cache hit, data is returned directly without network IO.