Endpoints¶

endpoint.Endpoint¶

Upstream host identifier.

{
  "address": "{...}"
}

address: (core.Address) The upstream host address.

Attention

The form of host address depends on the given cluster type. For STATIC or EDS, it is expected to be a direct IP address (or something resolvable by the specified resolver in the Address). For LOGICAL or STRICT DNS, it is expected to be hostname, and will be resolved via DNS.

endpoint.LbEndpoint¶

[endpoint.LbEndpoint proto]

An Endpoint that Envoy can route traffic to.

{
  "endpoint": "{...}",
  "health_status": "...",
  "metadata": "{...}",
  "load_balancing_weight": "{...}"
}

endpoint: (endpoint.Endpoint) Upstream host identifier

health_status: (core.HealthStatus) Optional health status when known and supplied by EDS server.

metadata: (core.Metadata) The endpoint metadata specifies values that may be used by the load balancer to select endpoints in a cluster for a given request. The filter name should be specified as envoy.lb. An example boolean key-value pair is canary, providing the optional canary status of the upstream host. This may be matched against in a route’s ForwardAction metadata_match field to subset the endpoints considered in cluster load balancing.

load_balancing_weight: (UInt32Value) The optional load balancing weight of the upstream host, in the range 1 - 128. Envoy uses the load balancing weight in some of the built in load balancers. The load balancing weight for an endpoint is divided by the sum of the weights of all endpoints in the endpoint’s locality to produce a percentage of traffic for the endpoint. This percentage is then further weighted by the endpoint’s locality’s load balancing weight from LocalityLbEndpoints. If unspecified, each host is presumed to have equal weight in a locality.

Attention

The limit of 128 is somewhat arbitrary, but is applied due to performance concerns with the current implementation and can be removed when this issue is fixed.

endpoint.LocalityLbEndpoints¶

[endpoint.LocalityLbEndpoints proto]

A group of endpoints belonging to a Locality. One can have multiple LocalityLbEndpoints for a locality, but this is generally only done if the different groups need to have different load balancing weights or different priorities.

{
  "locality": "{...}",
  "lb_endpoints": [],
  "load_balancing_weight": "{...}",
  "priority": "..."
}

locality: (core.Locality) Identifies location of where the upstream hosts run.

lb_endpoints: (endpoint.LbEndpoint) The group of endpoints belonging to the locality specified.

load_balancing_weight

(UInt32Value) Optional: Per priority/region/zone/sub_zone weight - range 1-128. The load balancing weight for a locality is divided by the sum of the weights of all localities at the same priority level to produce the effective percentage of traffic for the locality.

Locality weights are only considered when locality weighted load balancing is configured. These weights are ignored otherwise. If no weights are specificed when locality weighted load balancing is enabled, the cluster is assumed to have a weight of 1.

Attention

The limit of 128 is somewhat arbitrary, but is applied due to performance concerns with the current implementation and can be removed when this issue is fixed.

priority

(uint32) Optional: the priority for this LocalityLbEndpoints. If unspecified this will default to the highest priority (0).

Under usual circumstances, Envoy will only select endpoints for the highest priority (0). In the event all endpoints for a particular priority are unavailable/unhealthy, Envoy will fail over to selecting endpoints for the next highest priority group.

Priorities should range from 0 (highest) to N (lowest) without skipping.