io.envoyproxy.envoy.service.discovery.v2

Class HealthDiscoveryService.Stub

java.lang.Object

io.envoyproxy.envoy.service.discovery.v2.HealthDiscoveryService

io.envoyproxy.envoy.service.discovery.v2.HealthDiscoveryService.Stub

All Implemented Interfaces:

com.google.protobuf.Service, HealthDiscoveryService.Interface

Enclosing class:

HealthDiscoveryService

public static final class HealthDiscoveryService.Stub
extends HealthDiscoveryService
implements HealthDiscoveryService.Interface

Nested Class Summary

Nested classes/interfaces inherited from class io.envoyproxy.envoy.service.discovery.v2.HealthDiscoveryService

HealthDiscoveryService.BlockingInterface, HealthDiscoveryService.Interface, HealthDiscoveryService.Stub

Method Summary

Modifier and Type	Method and Description
void	fetchHealthCheck(com.google.protobuf.RpcController controller, HealthCheckRequestOrEndpointHealthResponse request, com.google.protobuf.RpcCallback<HealthCheckSpecifier> done) TODO(htuch): Unlike the gRPC version, there is no stream-based binding of request/response.
com.google.protobuf.RpcChannel	getChannel()
void	streamHealthCheck(com.google.protobuf.RpcController controller, HealthCheckRequestOrEndpointHealthResponse request, com.google.protobuf.RpcCallback<HealthCheckSpecifier> done) 1.

Methods inherited from class io.envoyproxy.envoy.service.discovery.v2.HealthDiscoveryService

callMethod, getDescriptor, getDescriptorForType, getRequestPrototype, getResponsePrototype, newBlockingStub, newReflectiveBlockingService, newReflectiveService, newStub

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getChannel

public com.google.protobuf.RpcChannel getChannel()

streamHealthCheck

public void streamHealthCheck(com.google.protobuf.RpcController controller,
                              HealthCheckRequestOrEndpointHealthResponse request,
                              com.google.protobuf.RpcCallback<HealthCheckSpecifier> done)

Description copied from class: 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 .envoy.service.discovery.v2.HealthCheckRequestOrEndpointHealthResponse) returns (stream .envoy.service.discovery.v2.HealthCheckSpecifier);

Specified by:

streamHealthCheck in interface HealthDiscoveryService.Interface

Specified by:

streamHealthCheck in class HealthDiscoveryService

fetchHealthCheck

public void fetchHealthCheck(com.google.protobuf.RpcController controller,
                             HealthCheckRequestOrEndpointHealthResponse request,
                             com.google.protobuf.RpcCallback<HealthCheckSpecifier> done)

Description copied from class: HealthDiscoveryService

 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(.envoy.service.discovery.v2.HealthCheckRequestOrEndpointHealthResponse) returns (.envoy.service.discovery.v2.HealthCheckSpecifier) { ... }

Specified by:

fetchHealthCheck in interface HealthDiscoveryService.Interface

Specified by:

fetchHealthCheck in class HealthDiscoveryService