Amazon Relational Database Service (RDS) | Automated Backups and Database Snapshots Flashcards
What are the minimum and maximum IOPS supported by Amazon RDS?
Automated Backups and Database Snapshots
Amazon Relational Database Service (RDS) | Database
The IOPS supported by Amazon RDS varies by database engine. For more details, please see the Amazon RDS User Guide.
What is the difference between automated backups and DB Snapshots?
Automated Backups and Database Snapshots
Amazon Relational Database Service (RDS) | Database
Amazon RDS provides two different methods for backing up and restoring your DB instance(s) automated backups and database snapshots (DB Snapshots).
The automated backup feature of Amazon RDS enables point-in-time recovery of your DB instance. When automated backups are turned on for your DB Instance, Amazon RDS automatically performs a full daily snapshot of your data (during your preferred backup window) and captures transaction logs (as updates to your DB Instance are made). When you initiate a point-in-time recovery, transaction logs are applied to the most appropriate daily backup in order to restore your DB instance to the specific time you requested. Amazon RDS retains backups of a DB Instance for a limited, user-specified period of time called the retention period, which by default is 7 days but can be set to up to 35 days. You can initiate a point-in-time restore and specify any second during your retention period, up to the Latest Restorable Time. You can use the DescribeDBInstances API to return the latest restorable time for you DB instance, which is typically within the last five minutes. Alternatively, you can find the Latest Restorable Time for a DB instance by selecting it in the AWS Management Console and looking in the “Description” tab in the lower panel of the Console.
DB Snapshots are user-initiated and enable you to back up your DB instance in a known state as frequently as you wish, and then restore to that specific state at any time. DB Snapshots can be created with the AWS Management Console, CreateDBSnapshot API, or create-db-snapshot command and are kept until you explicitly delete them.
The snapshots which Amazon RDS performs for enabling automated backups are available to you for copying (using the AWS console or the copy-db-snapshot command) or for the snapshot restore functionality. You can identify them using the “automated” Snapshot Type. In addition, you can identify the time at which the snapshot has been taken by viewing the “Snapshot Created Time” field. Alternatively, the identifier of the “automated” snapshots also contains the time (in UTC) at which the snapshot has been taken.
Please note: When you perform a restore operation to a point in time or from a DB Snapshot, a new DB Instance is created with a new endpoint (the old DB Instance can be deleted if so desired). This is done to enable you to create multiple DB Instances from a specific DB Snapshot or point in time.
Do I need to enable backups for my DB Instance or is it done automatically?
Automated Backups and Database Snapshots
Amazon Relational Database Service (RDS) | Database
By default, Amazon RDS enables automated backups of your DB Instance with a 7 day retention period. Free backup storage is limited to the size of your provisioned database and only applies to active DB Instances. For example, if you have 100 GB of provisioned database storage over the month, we will provide 100 GB-months of backup storage at no additional charge. If you would like to extend your backup retention period beyond one day, you can do so using the CreateDBInstance API (when creating a new DB Instance) or ModifyDBInstance API (for an existing DB Instance). You can use these APIs to change the RetentionPeriod parameter from 1 to the desired number of days. For more information on automated backups, please refer to the Amazon RDS User Guide.
What is a backup window and why do I need it? Is my database available during the backup window?
Automated Backups and Database Snapshots
Amazon Relational Database Service (RDS) | Database
The preferred backup window is the user-defined period of time during which your DB Instance is backed up. Amazon RDS uses these periodic data backups in conjunction with your transaction logs to enable you to restore your DB Instance to any second during your retention period, up to the LatestRestorableTime (typically up to the last few minutes). During the backup window, storage I/O may be briefly suspended while the backup process initializes (typically under a few seconds) and you may experience a brief period of elevated latency. There is no I/O suspension for Multi-AZ DB deployments, since the backup is taken from the standby.
Where are my automated backups and DB snapshots stored and how do I manage their retention?
Automated Backups and Database Snapshots
Amazon Relational Database Service (RDS) | Database
Amazon RDS DB snapshots and automated backups are stored in S3.
You can use the AWS Management Console, the ModifyDBInstance API, or the modify-db-instance command to manage the period of time your automated backups are retained by modifying the RetentionPeriod parameter. If you desire to turn off automated backups altogether, you can do so by setting the retention period to 0 (not recommended). You can manage your user-created DB Snapshots via the “Snapshots” section of the Amazon RDS Console. Alternatively, you can see a list of the user-created DB Snapshots for a given DB Instance using the DescribeDBSnapshots API or describe-db-snapshots command and delete snapshots with the DeleteDBSnapshot API or delete-db-snapshot command.
Why do I have more automated DB snapshots than the number of days in the retention period for my DB instance?
Automated Backups and Database Snapshots
Amazon Relational Database Service (RDS) | Database
It is normal to have 1 or 2 more automated DB snapshots than the number of days in your retention period. One extra automated snapshot is retained to ensure the ability to perform a point in time restore to any time during the retention period. For example, if your backup window is set to 1 day, you will require 2 automated snapshots to support restores to any within previous 24 hours. You may also see an additional automated snapshot as a new automated snapshot is always created before the oldest automated snapshot is deleted.
