The Envoy xDS APIs are defined as proto3 Protocol Buffers in the api tree. They support:

  • Streaming delivery of xDS API updates via gRPC. This reduces resource requirements and can lower the update latency.

  • A new REST-JSON API in which the JSON/YAML formats are derived mechanically via the proto3 canonical JSON mapping.

  • Delivery of updates via the filesystem, REST-JSON or gRPC endpoints.

  • Advanced load balancing through an extended endpoint assignment API and load and resource utilization reporting to management servers.

  • Stronger consistency and ordering properties when needed. The APIs still maintain a baseline eventual consistency model.

See the xDS protocol description for further details on aspects of xDS message exchange between Envoy and the management server.