Introduction
Invocation Logic
The following diagram shows the RPC service invocation logic of Capa:
- Service A is the service invoker, Service B is the service being invoked
- Service A initiates a service call to Service B through the Capa SDK
- Capa RPC API is a unified API specification
- The specific RPC implementation RPC Impl of the Capa RPC API can be found through the SPI mechanism
- Obtain the return data from Service B and return it to the service invoker Service A
API Design
Capa’s API design follows community standards:
The meanings of specific parameters are as follows:
| Parameter | Meaning |
|---|---|
| appId | Unique service ID within the same namespace |
| methodName | Method name of the service being invoked |
| request | Service request to be sent for invocation |
| httpExtension | HTTP request method |
| metadata | Metadata for sending requests (GRPC) or headers (HTTP) |
| clazz | Type of request response |
| type | Type of request response |
| invokeMethodRequest | Request object |