Oracle Cloud Infrastructure Documentation

Autoscaling

Autoscaling enables you to automatically adjust the number of Compute instances in an instance pool based on performance metrics such as CPU utilization. This helps you provide consistent performance for your end users during periods of high demand, and helps you reduce your costs during periods of low demand.

You select a performance metric to monitor, and set thresholds that the performance metric must reach to trigger an autoscaling event. When system usage meets a threshold, autoscaling dynamically allocates resources in near-real time. As load increases, instances are automatically provisioned: the instance pool scales out. As load decreases, instances are automatically removed: the instance pool scales in.

When an instance pool scales in, instances are terminated in this order: the number of instances is balanced across availability domains, and then balanced across fault domains. Finally, within a fault domain, the oldest instance is terminated first.

Autoscaling relies on performance metrics that are collected by the Monitoring service. These performance metrics are aggregated into one-minute time periods and then averaged across the instance pool. When three consecutive values (that is, the average metrics for three consecutive minutes) meet the threshold, an autoscaling event is triggered.

A cooldown period between autoscaling events lets the system stabilize at the updated level. The cooldown period starts when the instance pool reaches a steady state. Autoscaling continues to evaluate performance metrics during the cooldown period. When the cooldown period ends, autoscaling adjusts the instance pool's size again if needed.

For background information about the Monitoring service, see Monitoring Overview. For information about the metrics emitted by Compute instances, see Compute Instance Metrics.

Note

Autoscaling is not available in Oracle Cloud Infrastructure Government Cloud.

Warning

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 An IAM document that specifies who has what type of access to your resources. It is used in different ways: to mean an individual statement written in the policy language; to mean a collection of statements in a single, named "policy" document (which has an Oracle Cloud ID (OCID) assigned to it); and to mean the overall body of policies your organization uses to control access to resources. 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 A collection of related resources that can be accessed only by certain groups that have been given permission by an administrator in your organization. you should work in.

For administrators: For a typical policy that gives access to autoscaling configurations, see Let users manage Compute autoscaling configurations.

Tagging Resources

You can apply tags to your resources to help you organize them according to your business needs. You can apply tags at the time you create a resource, or you can update the resource later with the desired tags. For general information about applying tags, see Resource Tags.

Prerequisites

  • You have an instance pool. Optionally, you can attach a load balancer to the instance pool. For steps to create an instance pool and attach a load balancer, see Creating an Instance Pool.
  • Monitoring is enabled on the instances in the instance pool. For steps to enable monitoring, see Enabling Monitoring for Compute Instances.
  • The instance pool supports the maximum number of instances that you want to scale to. This limit is determined by your tenancy's service limits. For more information, see Service Limits.

Using the Console

To create an autoscaling configuration
To edit an autoscaling configuration
To edit an autoscaling policy
To disable an autoscaling configuration
To delete an autoscaling configuration
To manage tags for an autoscaling configuration

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 the Autoscaling API to manage autoscaling configurations and policies.