Limitations of Multi-AZ DB clusters for Amazon RDS - Amazon Relational Database Service
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Limitations of Multi-AZ DB clusters for Amazon RDS

A Multi-AZ DB cluster has a writer DB instance and two reader DB instances in three separate Availability Zones. Multi-AZ DB clusters provide high availability, increased capacity for read workloads, and lower latency when compared to Multi-AZ deployments. For more information about Multi-AZ DB clusters, see Multi-AZ DB cluster deployments for Amazon RDS.

The following limitations apply to Multi-AZ DB clusters.

  • Multi-AZ DB clusters don't support the following features:

    • IPv6 connections (dual-stack mode)

    • Cross-Region automated backups

    • Kerberos authentication

    • Modifying the port. As an alternative, you can restore a Multi-AZ DB cluster to a point in time and specify a different port.

    • Option groups

    • Point-in-time-recovery (PITR) for deleted clusters

    • Storage autoscaling by setting the maximum allocated storage. As an alternative, you can scale storage manually.

    • Stopping and starting the Multi-AZ DB cluster

    • Copying a snapshot of a Multi-AZ DB cluster

    • Encrypting an unencrypted Multi-AZ DB cluster

  • RDS for MySQL Multi-AZ DB clusters support only the following system stored procedures:

    • mysql.rds_rotate_general_log

    • mysql.rds_rotate_slow_log

    • mysql.rds_show_configuration

    • mysql.rds_set_external_master_with_auto_position

    • mysql.rds_set_configuration

  • RDS for PostgreSQL Multi-AZ DB clusters don't support the following extensions: aws_s3 and pg_transport.

  • RDS for PostgreSQL Multi-AZ DB clusters don't support using a custom DNS server for outbound network access.