Maintaining an Amazon Aurora DB cluster - Amazon Aurora
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Maintaining an Amazon Aurora DB cluster

Periodically, Amazon RDS performs maintenance on Amazon RDS resources. Maintenance most often involves updates to the following resources in your DB cluster:

  • Underlying hardware

  • Underlying operating system (OS)

  • Database engine version

Updates to the operating system most often occur for security issues. You should do them as soon as possible.

Some maintenance items require that Amazon RDS take your DB cluster offline for a short time. Maintenance items that require a resource to be offline include required operating system or database patching. Required patching is automatically scheduled only for patches that are related to security and instance reliability. Such patching occurs infrequently, typically once every few months. It seldom requires more than a fraction of your maintenance window.

Deferred DB cluster and instance modifications that you have chosen not to apply immediately are also applied during the maintenance window. For example, you might choose to change DB instance classes or cluster or DB parameter groups during the maintenance window. Such modifications that you specify using the pending reboot setting don't show up in the Pending maintenance list. For information about modifying a DB cluster, see Modifying an Amazon Aurora DB cluster.

To see the modifications that are pending for the next maintenance window, use the describe-db-clusters Amazon CLI command and check the PendingModifiedValues field.

Viewing pending maintenance

View whether a maintenance update is available for your DB cluster by using the RDS console, the Amazon CLI, or the RDS API. If an update is available, it is indicated in the Maintenance column for the DB cluster on the Amazon RDS console, as shown following.


            Offline patch available

If no maintenance update is available for a DB cluster, the column value is none for it.

If a maintenance update is available for a DB cluster, the following column values are possible:

  • required – The maintenance action will be applied to the resource and can't be deferred indefinitely.

  • available – The maintenance action is available, but it will not be applied to the resource automatically. You can apply it manually.

  • next window – The maintenance action will be applied to the resource during the next maintenance window.

  • In progress – The maintenance action is in the process of being applied to the resource.

If an update is available, you can take one of the actions:

  • If the maintenance value is next window, defer the maintenance items by choosing Defer upgrade from Actions. You can't defer a maintenance action if it has already started.

  • Apply the maintenance items immediately.

  • Schedule the maintenance items to start during your next maintenance window.

  • Take no action.

To take an action, choose the DB cluster to show its details, then choose Maintenance & backups. The pending maintenance items appear.


            Pending maintenance items

The maintenance window determines when pending operations start, but doesn't limit the total run time of these operations. Maintenance operations aren't guaranteed to finish before the maintenance window ends, and can continue beyond the specified end time. For more information, see The Amazon RDS maintenance window.

For information about updates to Amazon Aurora engines and instructions for upgrading and patching them, see Database engine updates for Amazon Aurora MySQL and Amazon Aurora PostgreSQL updates.

You can also view whether a maintenance update is available for your DB cluster by running the describe-pending-maintenance-actions Amazon CLI command.

Applying updates for a DB cluster

With Amazon RDS, you can choose when to apply maintenance operations. You can decide when Amazon RDS applies updates by using the RDS console, Amazon Command Line Interface (Amazon CLI), or RDS API.

Note

For RDS for SQL Server, an update to the underlying operating system can be applied by stopping and starting your DB instance, or by scaling your DB instance class up and then down again.

To manage an update for a DB cluster
  1. Sign in to the Amazon Web Services Management Console and open the Amazon RDS console at https://console.amazonaws.cn/rds/.

  2. In the navigation pane, choose Databases.

  3. Choose the DB cluster that has a required update.

  4. For Actions, choose one of the following:

    • Upgrade now

    • Upgrade at next window

      Note

      If you choose Upgrade at next window and later want to delay the update, you can choose Defer upgrade. You can't defer a maintenance action if it has already started.

      To cancel a maintenance action, modify the DB instance and disable Auto minor version upgrade.

To apply a pending update to a DB cluster, use the apply-pending-maintenance-action Amazon CLI command.

Example

For Linux, macOS, or Unix:

aws rds apply-pending-maintenance-action \ --resource-identifier arn:aws-cn:rds:us-west-2:001234567890:db:mysql-db \ --apply-action system-update \ --opt-in-type immediate

For Windows:

aws rds apply-pending-maintenance-action ^ --resource-identifier arn:aws-cn:rds:us-west-2:001234567890:db:mysql-db ^ --apply-action system-update ^ --opt-in-type immediate
Note

To defer a maintenance action, specify undo-opt-in for --opt-in-type. You can't specify undo-opt-in for --opt-in-type if the maintenance action has already started.

To cancel a maintenance action, run the modify-db-instance Amazon CLI command and specify --no-auto-minor-version-upgrade.

To return a list of resources that have at least one pending update, use the describe-pending-maintenance-actions Amazon CLI command.

Example

For Linux, macOS, or Unix:

aws rds describe-pending-maintenance-actions \ --resource-identifier arn:aws-cn:rds:us-west-2:001234567890:db:mysql-db

For Windows:

aws rds describe-pending-maintenance-actions ^ --resource-identifier arn:aws-cn:rds:us-west-2:001234567890:db:mysql-db

You can also return a list of resources for a DB cluster by specifying the --filters parameter of the describe-pending-maintenance-actions Amazon CLI command. The format for the --filters command is Name=filter-name,Value=resource-id,....

The following are the accepted values for the Name parameter of a filter:

  • db-instance-id – Accepts a list of DB instance identifiers or Amazon Resource Names (ARNs). The returned list only includes pending maintenance actions for the DB instances identified by these identifiers or ARNs.

  • db-cluster-id – Accepts a list of DB cluster identifiers or ARNs for Amazon Aurora. The returned list only includes pending maintenance actions for the DB clusters identified by these identifiers or ARNs.

For example, the following example returns the pending maintenance actions for the sample-cluster1 and sample-cluster2 DB clusters.

Example

For Linux, macOS, or Unix:

aws rds describe-pending-maintenance-actions \ --filters Name=db-cluster-id,Values=sample-cluster1,sample-cluster2

For Windows:

aws rds describe-pending-maintenance-actions ^ --filters Name=db-cluster-id,Values=sample-cluster1,sample-cluster2

To apply an update to a DB cluster, call the Amazon RDS API ApplyPendingMaintenanceAction operation.

To return a list of resources that have at least one pending update, call the Amazon RDS API DescribePendingMaintenanceActions operation.

The Amazon RDS maintenance window

Every DB cluster has a weekly maintenance window during which any system changes are applied. Think of the maintenance window as an opportunity to control when modifications and software patching occur. If a maintenance event is scheduled for a given week, it's initiated during the 30-minute maintenance window you identify. Most maintenance events also complete during the 30-minute maintenance window, although larger maintenance events may take more than 30 minutes to complete.

The 30-minute maintenance window is selected at random from an 8-hour block of time per region. If you don't specify a maintenance window when you create the DB cluster, RDS assigns a 30-minute maintenance window on a randomly selected day of the week.

RDS consumes some of the resources on your DB cluster while maintenance is being applied. You might observe a minimal effect on performance. For a DB instance, on rare occasions, a Multi-AZ failover might be required for a maintenance update to complete.

Following, you can find the time blocks for each region from which default maintenance windows are assigned.

Region Name Region Time Block
US East (Ohio) us-east-2 03:00–11:00 UTC
US East (N. Virginia) us-east-1 03:00–11:00 UTC
US West (N. California) us-west-1 06:00–14:00 UTC
US West (Oregon) us-west-2 06:00–14:00 UTC
Africa (Cape Town) af-south-1 03:00–11:00 UTC
Asia Pacific (Hong Kong) ap-east-1 06:00–14:00 UTC
Asia Pacific (Hyderabad) ap-south-2 06:30–14:30 UTC
Asia Pacific (Jakarta) ap-southeast-3 08:00–16:00 UTC
Asia Pacific (Melbourne) ap-southeast-4 11:00–19:00 UTC
Asia Pacific (Mumbai) ap-south-1 06:00–14:00 UTC
Asia Pacific (Osaka) ap-northeast-3 22:00–23:59 UTC
Asia Pacific (Seoul) ap-northeast-2 13:00–21:00 UTC
Asia Pacific (Singapore) ap-southeast-1 14:00–22:00 UTC
Asia Pacific (Sydney) ap-southeast-2 12:00–20:00 UTC
Asia Pacific (Tokyo) ap-northeast-1 13:00–21:00 UTC
Canada (Central) ca-central-1 03:00–11:00 UTC
Canada West (Calgary) ca-west-1 18:00–02:00 UTC
China (Beijing) cn-north-1 06:00–14:00 UTC
China (Ningxia) cn-northwest-1 06:00–14:00 UTC
Europe (Frankfurt) eu-central-1 21:00–05:00 UTC
Europe (Ireland) eu-west-1 22:00–06:00 UTC
Europe (London) eu-west-2 22:00–06:00 UTC
Europe (Milan) eu-south-1 02:00–10:00 UTC
Europe (Paris) eu-west-3 23:59–07:29 UTC
Europe (Spain) eu-south-2 02:00–10:00 UTC
Europe (Stockholm) eu-north-1 23:00–07:00 UTC
Europe (Zurich) eu-central-2 02:00–10:00 UTC
Israel (Tel Aviv) il-central-1 03:00–11:00 UTC
Middle East (Bahrain) me-south-1 06:00–14:00 UTC
Middle East (UAE) me-central-1 05:00–13:00 UTC
South America (São Paulo) sa-east-1 00:00–08:00 UTC
Amazon GovCloud (US-East) us-gov-east-1 17:00–01:00 UTC
Amazon GovCloud (US-West) us-gov-west-1 06:00–14:00 UTC

Adjusting the preferred DB cluster maintenance window

The Aurora DB cluster maintenance window should fall at the time of lowest usage and thus might need modification from time to time. Your DB cluster is unavailable during this time only if the updates that are being applied require an outage. The outage is for the minimum amount of time required to make the necessary updates.

To adjust the preferred DB cluster maintenance window
  1. Sign in to the Amazon Web Services Management Console and open the Amazon RDS console at https://console.amazonaws.cn/rds/.

  2. In the navigation pane, choose Databases.

  3. Choose the DB cluster for which you want to change the maintenance window.

  4. Choose Modify.

  5. In the Maintenance section, update the maintenance window.

  6. Choose Continue.

    On the confirmation page, review your changes.

  7. To apply the changes to the maintenance window immediately, choose Immediately in the Schedule of modifications section.

  8. Choose Modify cluster to save your changes.

    Alternatively, choose Back to edit your changes, or choose Cancel to cancel your changes.

To adjust the preferred DB cluster maintenance window, use the Amazon CLI modify-db-cluster command with the following parameters:

  • --db-cluster-identifier

  • --preferred-maintenance-window

Example

The following code example sets the maintenance window to Tuesdays from 4:00–4:30 AM UTC.

For Linux, macOS, or Unix:

aws rds modify-db-cluster \ --db-cluster-identifier my-cluster \ --preferred-maintenance-window Tue:04:00-Tue:04:30

For Windows:

aws rds modify-db-cluster ^ --db-cluster-identifier my-cluster ^ --preferred-maintenance-window Tue:04:00-Tue:04:30

To adjust the preferred DB cluster maintenance window, use the Amazon RDS ModifyDBCluster API operation with the following parameters:

  • DBClusterIdentifier

  • PreferredMaintenanceWindow

Automatic minor version upgrades for Aurora DB clusters

The Auto minor version upgrade setting specifies whether Aurora automatically applies upgrades to your DB cluster. These upgrades include new minor versions containing additional features and patches containing bug fixes.

This setting is turned on by default. For each new DB cluster, choose the appropriate value for this setting. This value is based on its importance, expected lifetime, and the amount of verification testing that you do after each upgrade.

For instructions on turning the Auto minor version upgrade setting on or off, see the following:

Important

We strongly recommend that for new and existing DB clusters, you apply this setting to the DB cluster and not to the DB instances in the cluster individually. If any DB instance in your cluster has this setting turned off, the DB cluster isn't automatically upgraded.

The following table shows how the Auto minor version upgrade setting works when applied at the cluster and instance levels.

Action Cluster setting Instance settings Cluster upgraded automatically?
You set it to True on the DB cluster. True True for all new and existing instances Yes
You set it to False on the DB cluster. False False for all new and existing instances No

It was set previously to True on the DB cluster.

You set it to False on at least one DB instance.

Changes to False False for one or more instances No

It was set previously to False on the DB cluster.

You set it to True on at least one DB instance, but not all instances.

False True for one or more instances, but not all instances No

It was set previously to False on the DB cluster.

You set it to True on all DB instances.

Changes to True True for all instances Yes

Automatic minor version upgrades are communicated in advance through an Amazon RDS DB cluster event with a category of maintenance and ID of RDS-EVENT-0156. For more information, see Amazon RDS event categories and event messages.

Automatic upgrades occur during the maintenance window. If the individual DB instances in the DB cluster have different maintenance windows from the cluster maintenance window, then the cluster maintenance window takes precedence.

For more information about engine updates for Aurora PostgreSQL, see Amazon Aurora PostgreSQL updates.

For more information about the Auto minor version upgrade setting for Aurora MySQL, see Enabling automatic upgrades between minor Aurora MySQL versions. For general information about engine updates for Aurora MySQL, see Database engine updates for Amazon Aurora MySQL.

Enabling automatic minor version upgrades for an Aurora DB cluster

Follow the general procedure in Modifying the DB cluster by using the console, CLI, and API.

Console

On the Modify DB cluster page, in the Maintenance section, select the Enable auto minor version upgrade check box.

Amazon CLI

Call the modify-db-cluster Amazon CLI command. Specify the name of your DB cluster for the --db-cluster-identifier option and true for the --auto-minor-version-upgrade option. Optionally, specify the --apply-immediately option to immediately enable this setting for your DB cluster.

RDS API

Call the ModifyDBCluster API operation and specify the name of your DB cluster for the DBClusterIdentifier parameter and true for the AutoMinorVersionUpgrade parameter. Optionally, set the ApplyImmediately parameter to true to immediately enable this setting for your DB cluster.

Enabling automatic minor version upgrades for individual DB instances in an Aurora DB cluster

Follow the general procedure in Modifying a DB instance in a DB cluster.

Console

On the Modify DB instance page, in the Maintenance section, select the Enable auto minor version upgrade check box.

Amazon CLI

Call the modify-db-instance Amazon CLI command. Specify the name of your DB instance for the --db-instance-identifier option and true for the --auto-minor-version-upgrade option. Optionally, specify the --apply-immediately option to immediately enable this setting for your DB instance. Run a separate modify-db-instance command for each DB instance in the cluster.

RDS API

Call the ModifyDBInstance API operation and specify the name of your DB cluster for the DBInstanceIdentifier parameter and true for the AutoMinorVersionUpgrade parameter. Optionally, set the ApplyImmediately parameter to true to immediately enable this setting for your DB instance. Call a separate ModifyDBInstance operation for each DB instance in the cluster.

You can use a CLI command such as the following to check the status of the AutoMinorVersionUpgrade setting for all of the DB instances in your Aurora MySQL clusters.

aws rds describe-db-instances \ --query '*[].{DBClusterIdentifier:DBClusterIdentifier,DBInstanceIdentifier:DBInstanceIdentifier,AutoMinorVersionUpgrade:AutoMinorVersionUpgrade}'

That command produces output similar to the following:

[ { "DBInstanceIdentifier": "db-writer-instance", "DBClusterIdentifier": "my-db-cluster-57", "AutoMinorVersionUpgrade": true }, { "DBInstanceIdentifier": "db-reader-instance1", "DBClusterIdentifier": "my-db-cluster-57", "AutoMinorVersionUpgrade": false }, { "DBInstanceIdentifier": "db-writer-instance2", "DBClusterIdentifier": "my-db-cluster-80", "AutoMinorVersionUpgrade": true }, ... output omitted ...

In this example, Enable auto minor version upgrade is turned off for the DB cluster my-db-cluster-57, because it's turned off for one of the DB instances in the cluster.

Choosing the frequency of Aurora MySQL maintenance updates

You can control whether Aurora MySQL upgrades happen frequently or rarely for each DB cluster. The best choice depends on your usage of Aurora MySQL and the priorities for your applications that run on Aurora. For information about the Aurora MySQL long-term stability (LTS) releases that require less frequent upgrades, see Aurora MySQL long-term support (LTS) releases.

You might choose to upgrade an Aurora MySQL cluster rarely if some or all of the following conditions apply:

  • Your testing cycle for your application takes a long time for each update to the Aurora MySQL database engine.

  • You have many DB clusters or many applications all running on the same Aurora MySQL version. You prefer to upgrade all of your DB clusters and associated applications at the same time.

  • You use both Aurora MySQL and RDS for MySQL. You prefer to keep the Aurora MySQL clusters and RDS for MySQL DB instances compatible with the same level of MySQL.

  • Your Aurora MySQL application is in production or is otherwise business-critical. You can't afford downtime for upgrades outside of rare occurrences for critical patches.

  • Your Aurora MySQL application isn't limited by performance issues or feature gaps that are addressed in subsequent Aurora MySQL versions.

If the preceding factors apply to your situation, you can limit the number of forced upgrades for an Aurora MySQL DB cluster. You do so by choosing a specific Aurora MySQL version known as the "Long-Term Support" (LTS) version when you create or upgrade that DB cluster. Doing so minimizes the number of upgrade cycles, testing cycles, and upgrade-related outages for that DB cluster.

You might choose to upgrade an Aurora MySQL cluster frequently if some or all of the following conditions apply:

  • The testing cycle for your application is straightforward and brief.

  • Your application is still in the development stage.

  • Your database environment uses a variety of Aurora MySQL versions, or Aurora MySQL and RDS for MySQL versions. Each Aurora MySQL cluster has its own upgrade cycle.

  • You are waiting for specific performance or feature improvements before you increase your usage of Aurora MySQL.

If the preceding factors apply to your situation, you can enable Aurora to apply important upgrades more frequently. To do so, upgrade an Aurora MySQL DB cluster to a more recent Aurora MySQL version than the LTS version. Doing so makes the latest performance enhancements, bug fixes, and features available to you more quickly.

Working with operating system updates

DB instances in Aurora MySQL and Aurora PostgreSQL DB clusters occasionally require operating system updates. Amazon RDS upgrades the operating system to a newer version to improve database performance and customers’ overall security posture. Typically, the updates take about 10 minutes. Operating system updates don't change the DB engine version or DB instance class of a DB instance.

We recommend that you update the reader DB instances in a DB cluster first, then the writer DB instance. We don't recommend updating reader and writer instances at the same time, because you might incur downtime in the event of a failover.

There are two types of operating system updates, differentiated by the description visible in the pending maintenance action on the DB instance:

  • Operating system distribution upgrade – Used to migrate to the latest supported major version of Amazon Linux. Its description in the pending maintenance action is New Operating System upgrade is available.

  • Operating system patch – Used to apply various security fixes and sometimes to improve database performance. Its description in the pending maintenance action is New Operating System patch is available.

Operating system updates can be either optional or mandatory:

  • An optional update can be applied at any time. While these updates are optional, we recommend that you apply them periodically to keep your RDS fleet up to date. RDS does not apply these updates automatically.

    To be notified when a new, optional operating system patch becomes available, you can subscribe to RDS-EVENT-0230 in the security patching event category. For information about subscribing to RDS events, see Subscribing to Amazon RDS event notification.

    Note

    RDS-EVENT-0230 doesn't apply to operating system distribution upgrades.

    Note

    If you received RDS-EVENT-0230 for an RDS for SQL Server DB instance, the OS update can't be applied via the apply-pending-maintenance action. For more information, see Applying updates for a DB cluster.

  • A mandatory update is required, and we send a notification before the mandatory update. The notification might contain a due date. Plan to schedule your update before this due date. After the specified due date, Amazon RDS automatically upgrades the operating system for your DB instance to the latest version during one of your assigned maintenance windows.

    Operating system distribution upgrades are mandatory.

Note

Staying current on all optional and mandatory updates might be required to meet various compliance obligations. We recommend that you apply all updates made available by RDS routinely during your maintenance windows.

You can use the Amazon Web Services Management Console or the Amazon CLI to get information about the type of operating system upgrade.

To get update information using the Amazon Web Services Management Console
  1. Sign in to the Amazon Web Services Management Console and open the Amazon RDS console at https://console.amazonaws.cn/rds/.

  2. In the navigation pane, choose Databases, and then select the DB instance.

  3. Choose Maintenance.

  4. In the Pending maintenance section, find the operating system update, and check the Description value.

In the Amazon Web Services Management Console, an operating system distribution upgrade has its Description set to New Operating System upgrade is available, as shown in the following image. This upgrade is mandatory.


                        Operating system distribution upgrade.

An operating system patch has its Description set to New Operating System patch is available, as shown in the following image.


                        Operating system patch.

To get update information from the Amazon CLI, use the describe-pending-maintenance-actions command.

aws rds describe-pending-maintenance-actions

The following output shows an operating system distribution upgrade.

{ "ResourceIdentifier": "arn:aws-cn:rds:us-east-1:123456789012:db:mydb1", "PendingMaintenanceActionDetails": [ { "Action": "system-update", "Description": "New Operating System upgrade is available" } ] }

The following output shows an operating system patch.

{ "ResourceIdentifier": "arn:aws-cn:rds:us-east-1:123456789012:db:mydb2", "PendingMaintenanceActionDetails": [ { "Action": "system-update", "Description": "New Operating System patch is available" } ] }

Availability of operating system updates

Operating system updates are specific to DB engine version and DB instance class. Therefore, DB instances receive or require updates at different times. When an operating system update is available for your DB instance based on its engine version and instance class, the update appears in the console. It can also be viewed by running Amazon CLI describe-pending-maintenance-actions command or by calling the RDS DescribePendingMaintenanceActions API operation. If an update is available for your instance, you can update your operating system by following the instructions in Applying updates for a DB cluster.