Rebooting a DB instance

You can stop and start the database service on your RDS DB instance in a single operation, called rebooting.

Use cases for rebooting a DB instance

Typically, you reboot your DB instance for maintenance reasons so that your changes take effect. The following use cases are common:

• Associating a new DB parameter group – When you associate a new DB parameter group with a DB instance, RDS applies the modified static and dynamic parameters only after the DB instance is rebooted. However, if you modify dynamic parameters in the DB parameter group after you have associated it with the DB instance, these changes are applied immediately without a reboot. For more information, see Working with parameter groups.

• Applying a change to a static parameter in an existing DB parameter group – When you change a static parameter and save the DB parameter group, the status of DB instances associated with this parameter group in the console changes to pending-reboot. The parameter change takes effect only after the associated DB instances are rebooted. When you change a dynamic parameter in an existing parameter group, the change takes effect immediately by default, without requiring a reboot.

  Note

  The pending-reboot status doesn't result in an automatic reboot during the next maintenance window. To apply the latest parameter changes to your DB instance, reboot the DB instance manually. For more information about parameter groups, see Working with parameter groups.

• Testing Multi-AZ failover – Your testing strategy for a Multi-AZ DB cluster might involve rebooting your primary DB instance to initiate a failover to a different AZ.

• Troubleshooting – You might encounter performance or other operational issues that necessitate a reboot. For example, your DB instance might be unresponsive.

How rebooting a DB instance works

When Amazon RDS reboots your DB instance it performs the following sequential tasks:

1. Stops the database service on your DB instance

2. Starts the database service on your DB instance

The reboot process leads to a brief outage. During this outage, the DB instance status is rebooting. An outage occurs for both a Single-AZ deployment and a Multi-AZ DB instance deployment, even when you reboot with a failover.

How rebooting a DB instance in a Multi-AZ deployment works

If the Amazon RDS DB instance is in a Multi-AZ deployment, you can reboot with a failover. This operation is useful to simulate a failure of a DB instance or restore operations to the original Availability Zone after a failover.

During the reboot with failover, Amazon RDS does the following

• Interrupts the database abruptly. The DB instance and its client sessions might not have time to shut down gracefully.

  Warning

  To avoid the possibility of data loss, we recommend stopping transactions on your DB instance before rebooting with a failover.

• Switches to a standby replica in another AZ automatically. The AZ change might not be reflected in the AWS Management Console, and in calls to the AWS CLI and RDS API, for several minutes.

• Updates the DNS record for the DB instance to point to the standby DB instance. As a result, you need to clean up and re-establish any existing connections to your DB instance. For more information, see Configuring and managing a Multi-AZ deployment.

• Creates an Amazon RDS event after the reboot.

On RDS for Microsoft SQL Server, the failover reboots only the primary DB instance. After the failover, the primary DB instance becomes the new secondary DB instance. Parameters might not be updated for Multi-AZ instances. For reboot without failover, both the primary and secondary DB instances reboot, and parameters are updated after the reboot. If the DB instance is unresponsive, we recommend reboot without failover.

Considerations when rebooting a DB instance

Before you reboot your instance, consider the following:

• For a DB instance with read replicas, you can reboot the source DB instance and its read replicas independently. After a reboot completes, replication resumes automatically.

• The reboot time depends on the crash recovery process, database activity at the time of reboot, and the behavior of your specific DB engine. To improve the reboot time, we recommend that you reduce database activity as much as possible during the reboot. This technique reduces rollback activity for in-transit transactions.

Prerequisites for rebooting a DB instance

Make sure that you meet the following prerequisites:

• Your DB instance must be in the available state. Your database can be unavailable for several reasons, such as an in-progress backup, a previously requested modification, or a maintenance window operation.

• If you force a failover to a different AZ, your DB instance must be configured for Multi-AZ.

• If you force a failover to a different AZ, we recommend first stopping transactions on your DB instance to prevent possible data loss.

Rebooting a DB instance: basic steps

You can reboot your DB instance using the AWS Management Console, AWS CLI, or RDS API.

Console

To reboot a DB instance

1. Sign in to the AWS Management Console and open the Amazon RDS console at https://console.aws.amazon.com/rds/.

2. In the navigation pane, choose Databases, and then choose the DB instance that you want to reboot.

3. For Actions, choose Reboot.

   The Reboot DB instance page appears.

4. (Optional) Choose Reboot with failover? to force a failover from one AZ to another.

5. Choose Reboot to reboot your DB instance.

   Alternatively, choose Cancel.

AWS CLI

To reboot a DB instance by using the AWS CLI, call the reboot-db-instance command.

Example Simple reboot

For Linux, macOS, or Unix:

aws rds reboot-db-instance \
    --db-instance-identifier mydbinstance

For Windows:

aws rds reboot-db-instance ^
    --db-instance-identifier mydbinstance

Example Reboot with failover

To force a failover from one AZ to the other in a Multi-AZ DB cluster, use the --force-failover parameter.

For Linux, macOS, or Unix:

aws rds reboot-db-instance \
    --db-instance-identifier mydbinstance \
    --force-failover

For Windows:

aws rds reboot-db-instance ^
    --db-instance-identifier mydbinstance ^
    --force-failover

RDS API

To reboot a DB instance by using the Amazon RDS API, call the RebootDBInstance operation.