What happens during an EC2 scheduled maintenance event and what preventative actions can I take?

Short description

Amazon EC2 maintenance is often a live-update to minimize customer impact. Because a live-update isn't always possible, a scheduled maintenance event can sometimes occur.

A scheduled maintenance event might require your instance to undergo one of the following:

• Stop or retire
• Reboot
• Lose network connectivity or power

The instance actions that your maintenance event requires depends on the instance configuration and the type of maintenance that is being performed.

Resolution

Depending on your situation, you can perform one of the following actions before the specified maintenance window:

Reschedule the maintenance event

If your instance must undergo a reboot, then reschedule the event so that your instance reboots at a date and time that suits you. For more information, see Reschedule a scheduled event.

Stop and start your instance

If your instance has an Amazon Elastic Block Store (Amazon EBS) volume as its root device, then complete maintenance by stopping and starting your instance. A stop and start migrates your instance to a new underlying host.

The stop and start changes the status of the scheduled maintenance event to Completed. The actions, when completed, can take up to an hour to be reflected in the status change. For more information, see View scheduled events.

Important: Stopping and restarting the instance changes the public IP address of your instance. It's a best practice to use an Elastic IP address instead of a public IP address when routing external traffic to your instance.

Automatically recover an instance

You can create an Amazon CloudWatch alarm that monitors an Amazon EC2 instance. You can configure the alarm to automatically recover the instance if the instance is impaired due to an underlying hardware failure. For more information, see Recover your instance.

Create an instance store-backed AMI

If the instance is based on an instance store or an ephemeral root volume, then you might face issues if your instance is scheduled to terminate rather than reboot. You must create an instance store-backed AMI, then migrate your data and relaunch the instance.

Let the maintenance event continue as scheduled

If the maintenance schedule is network connectivity, power maintenance, or a required reboot, then you can let the maintenance event continue as scheduled without intervention.

Related information

Amazon EC2 maintenance help page