Least Outstanding Requests steering

Least Outstanding Requests steering allows you to route traffic to origins that currently have the fewest number of outstanding requests.

This steering policy selects an origin by taking into consideration origin weights, as well as each origin’s number of in-flight requests. Origins with more pending requests are weighted proportionately less in relation to others.

Least Outstanding Requests steering is best to use if your origins are easily overwhelmed by a spike in concurrent requests. It supports adaptive routing and session affinity.

​​ Configure via the API

Pools
{
  "origin_steering": {
    "policy": "least_outstanding_requests"
  }
}

Refer to the API documentation Open API docs link for more information on the pool configuration.

​​ Limitations

Least Outstanding Requests steering can be configured for pools that are part of DNS-only load balancers, but is only supported in a no-operation, dummy form. When origin steering logic is applied for a pool on a DNS-only load balancer, all origin outstanding request counts are considered to be zero, meaning traffic is served solely based on origin weights.

Although it is configurable, it is not recommended to associate pools that use Least Outstanding Requests steering with DNS-only load balancers due to its partial support.