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Relational Database Service

Dec 22, 20246 min read

Relational Database Service

https://aws.amazon.com/rds/features/multi-az/

Overview

  • Managed PostgreSQL/MySQL/Oracle/SQL Server/DB2/Maria DB/Custom
  • RDS resources are provisioned similar to EC2
  • Security through
  • Backup/recovery
    • Automated backup with Point in time restore
      • Up to 35 days
    • Manual snapshots for longer term recovery
  • Maintenance
    • Managed and Schedule (with downtime)
  • Support for IAM authentication, integration with Secrets Manager
  • RDS Custom for access to and customize underlying instance (Oracle & SQL server)

Configuration Types

Single-AZ Configuration

  • Available engines (same as Multi-AZ with single standby)
  • Additional read capacity
    • none
      • read capacity is limited to primary
  • Automatic failover duration
    • Not available
      • a user-initiated point-in-time restore operation is required
        • This can take several hours
        • point-in-time restore snapshot frequency = about 5 mins
  • Minor version upgrades downtime
    • When using Automatic Minor Version Upgrades, minor version upgrade downtime occurs during the Amazon RDS 30-minute maintenance window
  • Higher resiliency to AZ outage
    • none
  • Lower jitter for transaction commits
    • no optimization for jitter

Multi-AZ configuration

  • Non-Aurora replicates synchronously
  • Aurora type replicates asynchronously

Multi-AZ with one standby

Specifics
  • Available engines (same as single-az deployment)
  • Additional Read capacity
    • None: Your standby DB instance is only a passive failover target for high availability
  • Automatic failover duration
    • as quickly as 60 seconds
    • failover time is independent of write throughput
  • Minor version upgrades downtime
    • When using Automatic Minor Version Upgrades, minor version upgrade downtime occurs during the Amazon RDS 30-minute maintenance window
  • Higher resiliency to AZ outage
    • In the event of an AZ failure, your workload will automatically failover to the up-to-date standby
  • Lower jitter for transaction commits
    • Access to Dedicated Log Volumes
How it works
  • In an Amazon RDS Multi-AZ deployment, Amazon RDS automatically creates a primary database (DB) instance and synchronously replicates the data to an instance in a different AZ. When it detects a failure, Amazon RDS automatically fails over to a standby instance without manual intervention.

Multi-AZ with two readable standbys

Specifics
  • Available engines
  • Additional Read capacity
    • Two standby DB instances act as failover targets and serve read traffic
    • Read capacity is determined by the overhead of write transactions from the primary
  • Lower latency
    • higher throughput for transaction commits
    • Up to 2x faster transaction commits compared to Amazon RDS Multi-AZ with one standby
  • Automatic failover duration
    • A new primary is available to serve your new workload in typically under 35 seconds
    • Failover time depends on length of replica lag
  • Minor version upgrades downtime
    • Typically under 1 second when customers add an open source or Amazon RDS Proxy to their deployment
    • Typically under 35 seconds with Multi-AZ with two readable standbys alone
  • Higher resiliency to AZ outage
    • In the event of a failure, one of the two remaining standbys will takeover and serve the workload (writes) from the primary
  • Lower jitter for transaction commits
    • Uses local storage for transactional logs to reduce jitter
How it works

Deploy highly available, durable MySQL or PostgreSQL databases in three AZs using Amazon RDS Multi-AZ with two readable standbys. Gain automatic failovers in typically under 35 seconds, up to 2x faster transaction commit latency compared to Amazon RDS Multi-AZ with one standby, additional read capacity, and a choice of AWS Graviton2– or Intel–based instances for compute.

Pricing

For Single-AZ deployments, Multi-AZ deployments with one standby instance, and Multi-AZ deployments with two readable standbys, pricing is per DB instance-hour consumed, from the time a DB instance is launched until it is stopped or deleted. Partial DB instance-hours are billed in one-second increments with a 10 minute minimum charge following a billable status change such as creating, starting, or modifying the DB instance class.

Specifics
  • Available engines
  • Additional Read capacity
    • Two standby DB instances act as failover targets and serve read traffic
    • Read capacity is determined by the overhead of write transactions from the primary
  • Lower latency
    • higher throughput for transaction commits
    • Up to 2x faster transaction commits compared to Amazon RDS Multi-AZ with one standby
  • Automatic failover duration
    • A new primary is available to serve your new workload in typically under 35 seconds
    • Failover time depends on length of replica lag
  • Minor version upgrades downtime
    • Typically under 1 second when customers add an open source or Amazon RDS Proxy to their deployment
    • Typically under 35 seconds with Multi-AZ with two readable standbys alone
  • Higher resiliency to AZ outage
    • In the event of a failure, one of the two remaining standbys will takeover and serve the workload (writes) from the primary
  • Lower jitter for transaction commits
    • Uses local storage for transactional logs to reduce jitter
How it works

Deploy highly available, durable MySQL or PostgreSQL databases in three AZs using Amazon RDS Multi-AZ with two readable standbys. Gain automatic failovers in typically under 35 seconds, up to 2x faster transaction commit latency compared to Amazon RDS Multi-AZ with one standby, additional read capacity, and a choice of AWS Graviton2– or Intel–based instances for compute.

Customers
SysCloud

SysCloud creates automatic backups for critical software as a service (SaaS) applications, monitors for malicious files, and delivers powerful insights about your data and compliance —all from one dashboard. SysCloud uses Amazon RDS Multi-AZ with two readable standbys for its internal monitoring system: “The new Amazon RDS Multi-AZ deployment option offers us a cost-efficient way to achieve better performance, availability, and read scalability,” said Vikram Srinivasan, Director, Infrastructure at SysCloud. “With the new Amazon RDS Multi-AZ deployment option, we expect to create a better experience for our customers.”

Multi-Region configuration

read replica configuration

  • main purpose is scalability
  • replicates asynchronously
  • can be single AZ, Cross-AZ, or Cross Region

RDS Custom

RDS Custom for Oracle

  • allows access to and customization of your underlying database server hose and OS

https://aws.amazon.com/blogs/aws/amazon-rds-custom-for-oracle-newcontrol-capabilities-in-database-environment/

RDS Custom for SQL Server

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