Overview of Load Balancer

Learn how Load Balancer provides automated traffic distribution from one entry point to multiple servers reachable from your virtual cloud network.

The Load Balancer service provides automated traffic distribution from one entry point to multiple servers reachable from your virtual cloud network (VCN). The service offers a load balancer with your choice of a public or private IP address, and provisioned bandwidth.


Watch a video introduction to the Load Balancer service.

A load balancer improves resource utilization, facilitates scaling, and helps ensure high availability. You can configure multiple load balancing policies and application-specific health checks  to ensure that the load balancer directs traffic only to healthy instances. The load balancer can reduce your maintenance window by draining traffic from an unhealthy application server before you remove it from service for maintenance.

This overview contains the following separate topics:

You can also view topics on the following load balancer-related subjects:

Resource Identifiers

Most types of Oracle Cloud Infrastructure resources have a unique, Oracle-assigned identifier called an Oracle Cloud ID (OCID). For information about the OCID format and other ways to identify your resources, see Resource Identifiers.

Monitoring Resources

Use Monitoring to query metrics and manage alarms. Metrics and alarms help monitor the health, capacity, and performance of your cloud resources.

For information about monitoring the traffic passing through your load balancer, see Load Balancer Metrics.

Authentication and Authorization

Each service in Oracle Cloud Infrastructure integrates with IAM for authentication and authorization, for all interfaces (the Console, SDK or CLI, and REST API).

An administrator in your organization needs to set up groups , compartments , and policies  that control which users can access which services, which resources, and the type of access. For example, the policies control who can create new users, create and manage the cloud network, launch instances, create buckets, download objects, and so on. For more information, see Getting Started with Policies. For specific details about writing policies for each of the different services, see Policy Reference.

If you're a regular user (not an administrator) who needs to use the Oracle Cloud Infrastructure resources that your company owns, contact your administrator to set up a user ID for you. The administrator can confirm which compartment or compartments you should be using.

Limits on Load Balancing Resources

See Service Limits for a list of applicable limits and instructions for requesting a limit increase.

Other limits include:

  • You cannot convert an AD-specific load balancer to a regional load balancer or the reverse.

  • The maximum number of concurrent connections is limited when you use stateful security rules for your load balancer subnets. In contrast, no theoretical limit on concurrent connections exists if you use stateless security rules. The practical limitations depend on various factors. The larger your load balancer shape, the greater the connection capacity. Other considerations include system memory, TCP timeout periods, TCP connection state, and so forth.


    To accommodate high-volume traffic, we recommend that you use stateless security rules for your load balancer subnets. See Stateful Versus Stateless Rules for more information.

  • Each load balancer has the following configuration limits:

    • One IPv4 address and one IPv6 address

    • 16 backend sets

    • 512 backend servers per backend set

    • 512 backend servers total

    • 16 listeners

    • 16 virtual hostnames