Configuring Multi-AZ deployment - Amazon Redshift

Configuring Multi-AZ deployment

Amazon Redshift supports multiple Availability Zones (Multi-AZ) deployments for provisioned RA3 clusters. By using Multi-AZ deployments, your Amazon Redshift data warehouse can continue operating in failure scenarios when an unexpected event happens in an Availability Zone. A Multi-AZ deployment deploys compute resources in two Availability Zones (AZs) and these compute resources can be accessed through a single endpoint. In the event of an entire Availability Zone failure, the remaining compute resources in the second Availability Zone are available to continue processing workloads. Amazon Redshift charges the same hourly compute rates for RA3 when running a Multi-AZ data warehouse. Storage costs remain the same as it is shared across all Availability Zones within and AWS Region.

Currently, Amazon Redshift supports zero Recovery Point Objective (RPO) that allows data to be current and up-to-date in the event of a failure. With Multi-AZ deployment, Amazon Redshift further enhances its existing recovery capabilities and reduces its Recovery Time Objective (RTO). This is possible because a Multi-AZ deployment can recover faster from a failure or disaster thereby elevating the Amazon Redshift Service Level Agreement (SLA) to 99.99% as compared to 99.9% with a Single-AZ data warehouse.

Setting up Multi-AZ deployment

To set up a Multi-AZ deployment, select the Multi-AZ option and specify the number of compute nodes to provision in each Availability Zone. Amazon Redshift automatically deploys equal compute resources across two Availability Zones and all compute resources are always available for both read and write processing during normal operation. This allows a Multi-AZ deployment to act as a single data warehouse with a single endpoint, removing the need for application changes when a disaster occurs. Although a Multi-AZ deployment processes an individual query using the compute resources residing in only one Availability Zone, it can automatically distribute processing of multiple simultaneous queries to both Availability Zones to boost overall throughput for high concurrency workloads.

You can also convert an existing Single-AZ data warehouse into a Multi-AZ data warehouse or vice versa. Everything remains the same except that additional compute resources are provisioned in the second Availability Zone. When migrating to Multi-AZ from an existing Single-AZ cluster, you might be required to double the number of cluster nodes needed, to facilitate that single query performance is maintained. Most workloads observe an increase in overall query processing throughput with a Multi-AZ data warehouse as there is twice the amount of compute resources available.

In the event of a failure in an Availability Zone, Amazon Redshift continues operating by using the resources in the remaining Availability Zone automatically. However, user connections might be lost and must be re-established. In addition, queries that were running in the failed Availability Zone can fail and must be retried. However, you can reconnect to your cluster and reschedule queries immediately, and Amazon Redshift will process the queries in the remaining Availability Zone. Queries issued at or after a failure occurs might experience runtime delays while the Multi-AZ data warehouse is recovering.

Note

To achieve better performance and higher availability, we recommend that you use SNAPSHOT ISOLATION with your Multi-AZ clusters. For more information, see CREATE DATABASE.

Limitations

A Multi-AZ data warehouse has the same functional capabilities as a Single-AZ data warehouse, except for the following limitations that apply to a Multi-AZ data warehouse:

  • You can't create an unencrypted Multi-AZ data warehouse. Make sure to add an encryption when creating a new Multi-AZ data warehouse, converting a Single-AZ data warehouse into a Multi-AZ data warehouse, or converting a Single-AZ data warehouse into a Multi-AZ data warehouse.

  • You can't create a single node Multi-AZ deployment for any of the RA3 instance types. Choose 2 or more nodes per Availability Zone while creating a Multi-AZ deployment.

  • Zero-ETL integrations aren't supported on target data warehouses that are configured for Multi-AZ deployment.

  • Amazon Redshift doesn't support a subnet configuration that can support fewer than three Availability Zones. In other words, the configured subnet group requires three more subnets.

  • You can't relocate a Multi-AZ deployment to another Availability Zone. Relocation will be automatically determined and conducted by Amazon Redshift when using Multi-AZ deployment.

  • You can't pause or resume a Multi-AZ deployment.

  • You can't run your Multi-AZ deployment outside of the supported port ranges 5431 to 5455 and 8191 to 8215.

  • You can't use STL, SVCS, SVL, SVV, STV views with Multi-AZ deployments as they only support system monitoring views (SYS_* views). Change your monitoring queries to use system monitoring views (SYS_* views).

  • You can't attach an Elastic IP address to an existing cluster with Multi-AZ enabled.

  • You can't convert a cluster with an attached Elastic IP address from Single-AZ to Multi-AZ.

  • Amazon Redshift Multi-AZ deployment is available in the following AWS Regions:

    • US East (Ohio) (us-east-2)

    • US East (N. Virginia) (us-east-1)

    • US West (Oregon) (us-west-2)

    • Africa (Cape Town) (af-south-1)

    • Asia Pacific (Hong Kong) (ap-east-1)

    • Asia Pacific (Hyderabad) (ap-south-2)

    • Asia Pacific (Jakarta) (ap-southeast-3)

    • Asia Pacific (Melbourne) (ap-southeast-4)

    • Asia Pacific (Mumbai) (ap-south-1)

    • Asia Pacific (Osaka) (ap-northeast-3)

    • Asia Pacific (Seoul) (ap-northeast-2)

    • Asia Pacific (Singapore) (ap-southeast-1)

    • Asia Pacific (Sydney) (ap-southeast-2)

    • Asia Pacific (Tokyo) (ap-northeast-1)

    • Canada (Central) (ca-central-1)

    • Europe (Frankfurt) (eu-central-1)

    • Europe (Ireland) (eu-west-1)

    • Europe (Milan) (eu-south-1)

    • Europe (Paris) (eu-west-3)

    • Europe (Spain) (eu-south-2)

    • Europe (Stockholm) (eu-north-1)

    • Europe (Zurich) (eu-central-2)

    • Israel (Tel Aviv) (il-central-1)

    • Middle East (Bahrain) (me-south-1)

    • Middle East (UAE) (me-central-1)