Managing Backend Sets

This topic describes how to create and delete backend sets for use with a load balancer. For information about managing load balancers, see Managing Load Balancers.


Avoid entering confidential information when assigning descriptions, tags, or friendly names to your cloud resources through the Oracle Cloud Infrastructure Console, API, or CLI.

Required IAM Policy

To use Oracle Cloud Infrastructure, you must be given the required type of access in a policy  written by an administrator, whether you're using the Console or the REST API with an SDK, CLI, or other tool. If you try to perform an action and get a message that you don’t have permission or are unauthorized, confirm with your administrator the type of access you've been granted and which compartment  you should work in.

For administrators: For a typical policy that gives access to load balancers and their components, see Let network admins manage load balancers.

Also, be aware that a policy statement with inspect load-balancers gives the specified group the ability to see all information about the load balancers. For more information, see Details for Load Balancing.

If you're new to policies, see Getting Started with Policies and Common Policies.

Working with Backend Sets

A backend set is a logical entity defined by a load balancing policy, a health check policy, and a list of backend servers. To create a backend set, you must specify a load balancing policy and health check script, and then add a list of backend servers (Compute instances). SSL and session persistence configuration is optional. A backend set must be associated with one or more listeners for the load balancer to work.

You cannot delete a backend set used by an active listener.

Changing the load balancing policy of a backend set temporarily interrupts traffic and can drop active connections.

For background information on the Oracle Cloud Infrastructure Load Balancing, see Overview of Load Balancing.

Click Backend Sets under Resources in the Load Balancer Details page to display the Backend Sets page. This page contains a button for creating new backend sets.

Health Status

The Load Balancing service provides health status indicators that use your health check policies to report on the general health of your load balancers and their components. You can see health status indicators on the Console List and Details pages for load balancers, backend sets, and backend servers. You also can use the Load Balancing API to retrieve this information.

For general information about health status indicators, see Editing Health Check Policies.

Backend Set Health Summary

The Console list of a load balancer's backend sets provides health status summaries that indicate the overall health of each backend set. Health status indicators have four levels. The meaning of each level is:

  • OK: All backend servers in the backend set return a status of OK.
  • WARNING: Both of the following conditions are true:

    • Half or more of the backend set's backend servers return a status of OK.
    • At least one backend server returns a status of WARNING, CRITICAL, or UNKNOWN.
  • CRITICAL: Fewer than half of the backend set's backend servers return a status of OK.
  • UNKNOWN: At least one of the following conditions is true:

    • More than half of the backend set's backend servers return a status of UNKNOWN.
    • The system could not retrieve metrics for any reason.
    • The backend set does not have a listener attached.

For guidance on detecting and correcting common issues, see Using Health Status.

Backend Set Health Details

The backend set Details page provides the same Overall Health status indicator found in the load balancer's list of backend sets. It also includes counters for the Backend Health status values reported by the backend set's child backend servers.

The health status counter badges indicate the following:

  • The number of child entities reporting the indicated health status level.
  • If a counter corresponds to the overall health, the badge has a fill color.
  • If a counter has a zero value, the badge has a light gray outline and no fill color.

Creating Backend Sets

To create a backend set

Editing Backend Sets

To edit a backend set

Deleting Backend Sets

To delete a backend set

Using the API

For information about using the API and signing requests, see REST APIs and Security Credentials. For information about SDKs, see Software Development Kits and Command Line Interface.

Use these API operations to manage load balancer backend sets: