Amazon Relational Database Service (Amazon RDS) supports two easy-to-use options for ensuring High Availability of your relational database.

For your MySQL, MariaDB, PostgreSQL, Oracle, and SQL Server database (DB) instances, you can use Amazon RDS Multi-AZ deployments. When you provision a Multi-AZ DB instance, Amazon RDS automatically creates a primary DB instance and synchronously replicates the data to a standby instance in a different Availability Zone (AZ). In case of an infrastructure failure, Amazon RDS performs an automatic failover to the standby DB instance. Since the endpoint for your DB instance remains the same after a failover, your application can resume database operation without the need for manual administrative intervention. Learn more >>

The Amazon Aurora PostgreSQL and Amazon Aurora MySQL engines include additional High Availability options. Even with a single database instance, Amazon Aurora increases availability by replicating your data six ways across three Availability Zones. This means that your DB cluster can tolerate a failure of an Availability Zone without any loss of data and only a brief interruption of service.

In addition, you can choose to run one or more Replicas in an Amazon Aurora DB cluster. If the primary instance in the DB cluster fails, RDS automatically promotes an existing Aurora Replica to be the new primary instance and updates the server endpoint so that your application can continue operation with no manual intervention. If no Replicas have been provisioned, RDS will automatically create a new replacement DB instance for you when a failure is detected. Learn more>>

Enhanced Durability

Enhanced Durability

Multi-AZ deployments for the MySQL, MariaDB, Oracle, and PostgreSQL engines utilize synchronous physical replication to keep data on the standby up-to-date with the primary. Multi-AZ deployments for the SQL Server engine use synchronous logical replication to achieve the same result, employing SQL Server-native Mirroring technology. 

Amazon Aurora automatically replicates your volume six ways across three Availability Zones. Amazon Aurora storage is fault-tolerant, transparently handling the loss of up to two copies of data without affecting database write availability and up to three copies without affecting read availability.

Increased Availability

Increased Availability

You also benefit from enhanced database availability when running Multi-AZ deployments. If an Availability Zone failure or DB Instance failure occurs, your availability impact is limited to the time automatic fail-over takes to complete which is typically under a minute for Amazon Aurora and one to two minutes for other database engines.

When operations such as DB Instance scaling or system upgrades like OS patching are initiated for Multi-AZ deployments, they are applied first on the standby prior to an automatic failover. As a result, your availability impact is limited only to the time required for automatic failover to complete.

Automatic Fail-over

No Administrative Intervention

Amazon RDS monitors the health of your database instances and initiates a failover automatically in response to a variety of failure conditions. This includes loss of availability in an Availability Zone, loss of network connectivity to the instance, and compute failure or storage failure. DB instance failover is fully automatic and requires no administrative intervention.

Amazon RDS detects and automatically recovers from the most common failure scenarios so that you can resume database operations as quickly as possible without needing any manual operations.

Multi-AZ configurations for MySQL, MariaDB, Oracle, and PostgreSQL are covered by the Amazon RDS Service Level Agreement ("SLA"). The RDS SLA affirms that AWS will use commercially reasonable efforts to make Multi-AZ instances of Amazon RDS available with a Monthly Uptime Percentage of at least 99.95% during any monthly billing cycle. In the event Amazon RDS does not meet the Monthly Uptime Percentage commitment, affected customers will be eligible to receive a service credit.

It's easy to change your existing Amazon RDS instances to Multi-AZ.  You can use the RDS console to convert existing DB instances to Multi-AZ deployments by modifying the DB instance and specifying the Multi-AZ option.

Want to know more?

Drop our AWS experts a line.

Want to know more?
Drop our AWS experts a line
Want to know more?
Drop our AWS experts a line
Want to know more?
Drop our AWS experts a line
Want to know more?
Drop our AWS experts a line
Want to know more?
Drop our AWS experts a line
Want to know more?
Drop our AWS experts a line
Want to know more?
Drop our AWS experts a line
Want to know more?
Drop our AWS experts a line
Want to know more?
Drop our AWS experts a line
Want to know more?
Drop our AWS experts a line
Want to know more?
Drop our AWS experts a line