envoy.service.discovery.v3alpha.hds.proto Maven / Gradle / Ivy
syntax = "proto3";
package envoy.service.discovery.v3alpha;
option java_outer_classname = "HdsProto";
option java_multiple_files = true;
option java_package = "io.envoyproxy.envoy.service.discovery.v3alpha";
option java_generic_services = true;
import "envoy/api/v3alpha/core/base.proto";
import "envoy/api/v3alpha/core/health_check.proto";
import "envoy/api/v3alpha/endpoint/endpoint.proto";
import "google/api/annotations.proto";
import "google/protobuf/duration.proto";
// [#proto-status: experimental]
// HDS is Health Discovery Service. It compliments Envoy’s health checking
// service by designating this Envoy to be a healthchecker for a subset of hosts
// in the cluster. The status of these health checks will be reported to the
// management server, where it can be aggregated etc and redistributed back to
// Envoy through EDS.
service HealthDiscoveryService {
// 1. Envoy starts up and if its can_healthcheck option in the static
// bootstrap config is enabled, sends HealthCheckRequest to the management
// server. It supplies its capabilities (which protocol it can health check
// with, what zone it resides in, etc.).
// 2. In response to (1), the management server designates this Envoy as a
// healthchecker to health check a subset of all upstream hosts for a given
// cluster (for example upstream Host 1 and Host 2). It streams
// HealthCheckSpecifier messages with cluster related configuration for all
// clusters this Envoy is designated to health check. Subsequent
// HealthCheckSpecifier message will be sent on changes to:
// a. Endpoints to health checks
// b. Per cluster configuration change
// 3. Envoy creates a health probe based on the HealthCheck config and sends
// it to endpoint(ip:port) of Host 1 and 2. Based on the HealthCheck
// configuration Envoy waits upon the arrival of the probe response and
// looks at the content of the response to decide whether the endpoint is
// healthy or not. If a response hasn't been received within the timeout
// interval, the endpoint health status is considered TIMEOUT.
// 4. Envoy reports results back in an EndpointHealthResponse message.
// Envoy streams responses as often as the interval configured by the
// management server in HealthCheckSpecifier.
// 5. The management Server collects health statuses for all endpoints in the
// cluster (for all clusters) and uses this information to construct
// EndpointDiscoveryResponse messages.
// 6. Once Envoy has a list of upstream endpoints to send traffic to, it load
// balances traffic to them without additional health checking. It may
// use inline healthcheck (i.e. consider endpoint UNHEALTHY if connection
// failed to a particular endpoint to account for health status propagation
// delay between HDS and EDS).
// By default, can_healthcheck is true. If can_healthcheck is false, Cluster
// configuration may not contain HealthCheck message.
// TODO(htuch): How is can_healthcheck communicated to CDS to ensure the above
// invariant?
// TODO(htuch): Add @amb67's diagram.
rpc StreamHealthCheck(stream HealthCheckRequestOrEndpointHealthResponse)
returns (stream HealthCheckSpecifier) {
}
// TODO(htuch): Unlike the gRPC version, there is no stream-based binding of
// request/response. Should we add an identifier to the HealthCheckSpecifier
// to bind with the response?
rpc FetchHealthCheck(HealthCheckRequestOrEndpointHealthResponse) returns (HealthCheckSpecifier) {
option (google.api.http) = {
post: "/v3alpha/discovery:health_check"
body: "*"
};
}
}
// Defines supported protocols etc, so the management server can assign proper
// endpoints to healthcheck.
message Capability {
// Different Envoy instances may have different capabilities (e.g. Redis)
// and/or have ports enabled for different protocols.
enum Protocol {
HTTP = 0;
TCP = 1;
REDIS = 2;
}
repeated Protocol health_check_protocols = 1;
}
message HealthCheckRequest {
envoy.api.v3alpha.core.Node node = 1;
Capability capability = 2;
}
message EndpointHealth {
envoy.api.v3alpha.endpoint.Endpoint endpoint = 1;
envoy.api.v3alpha.core.HealthStatus health_status = 2;
}
message EndpointHealthResponse {
repeated EndpointHealth endpoints_health = 1;
}
message HealthCheckRequestOrEndpointHealthResponse {
oneof request_type {
HealthCheckRequest health_check_request = 1;
EndpointHealthResponse endpoint_health_response = 2;
}
}
message LocalityEndpoints {
envoy.api.v3alpha.core.Locality locality = 1;
repeated envoy.api.v3alpha.endpoint.Endpoint endpoints = 2;
}
// The cluster name and locality is provided to Envoy for the endpoints that it
// health checks to support statistics reporting, logging and debugging by the
// Envoy instance (outside of HDS). For maximum usefulness, it should match the
// same cluster structure as that provided by EDS.
message ClusterHealthCheck {
string cluster_name = 1;
repeated envoy.api.v3alpha.core.HealthCheck health_checks = 2;
repeated LocalityEndpoints locality_endpoints = 3;
}
message HealthCheckSpecifier {
repeated ClusterHealthCheck cluster_health_checks = 1;
// The default is 1 second.
google.protobuf.Duration interval = 2;
}