Endpoint configuration¶

Endpoint discovery architecture overview

ClusterLoadAssignment¶

Each route from RDS will map to a single cluster or traffic split across clusters using weights expressed in the RDS WeightedCluster.

With EDS, each cluster is treated independently from a LB perspective, with LB taking place between the Localities within a cluster and at a finer granularity between the hosts within a locality. The percentage of traffic for each endpoint is determined by both its load_balancing_weight, and the load_balancing_weight of its locality. First, a locality will be selected, then an endpoint within that locality will be chose based on its weight.

{
  "cluster_name": "...",
  "endpoints": [],
  "policy": "{...}"
}

cluster_name: (string, REQUIRED) Name of the cluster. This will be the service_name value if specified in the cluster EdsClusterConfig.

endpoints: (repeated endpoint.LocalityLbEndpoints) List of endpoints to load balance to.

policy: (ClusterLoadAssignment.Policy) Load balancing policy settings.

ClusterLoadAssignment.Policy¶

[ClusterLoadAssignment.Policy proto]

Load balancing policy settings.

{
  "overprovisioning_factor": "{...}",
  "endpoint_stale_after": "{...}"
}

overprovisioning_factor

(UInt32Value) Priority levels and localities are considered overprovisioned with this factor (in percentage). This means that we don’t consider a priority level or locality unhealthy until the percentage of healthy hosts multiplied by the overprovisioning factor drops below 100. With the default value 140(1.4), Envoy doesn’t consider a priority level or a locality unhealthy until their percentage of healthy hosts drops below 72%. For example:

{ "overprovisioning_factor": 100 }

Read more at priority levels and localities.

endpoint_stale_after: (Duration) The max time until which the endpoints from this assignment can be used. If no new assignments are received before this time expires the endpoints are considered stale and should be marked unhealthy. Defaults to 0 which means endpoints never go stale.