Amazon Relational Database Service (or Amazon RDS) is a distributed relational database service by Amazon Web Services (AWS). It is a web service running "in the cloud" designed to simplify the setup, operation, and scaling of a relational database for use in applications. Complex administration processes like patching the database software, backing up databases and enabling point-in-time recovery are managed automatically. Scaling storage and compute resources can be performed by a single API call.
Contents
- Features
- Multi AZ deployment
- Read replicas
- Performance metrics and monitoring
- RDS Costs
- Database instance types
- Competitors and alternatives
- References
Amazon RDS was first released on 22 October 2009, supporting MySQL databases. This was followed by support for Oracle Database in June 2011, Microsoft SQL Server in May 2012, PostgreSQL in November 2013, and MariaDB (a fork of MySQL) in October 2015.
In November 2014 AWS announced Amazon Aurora, a MySQL-compatible database offering enhanced high availability and performance.
Features
A new DB instance can be launched from the AWS Management Console or using the Amazon RDS APIs.
Amazon RDS offers different features to support different use cases. Some of the major features are:
Multi AZ deployment
Multi-Availability Zone deployments are targeted for production environments. Multi-AZ deployments aim to provide enhanced availability and data durability for MySQL instances. When a database instance is created or modified to run as a Multi-AZ deployment, Amazon RDS automatically provisions and maintains a synchronous “standby” replica in a different Availability Zone (independent infrastructure in a physically separate location). In the event of planned database maintenance or unplanned service disruption, Amazon RDS automatically fails over to the up-to-date standby, allowing database operations to resume without administrative intervention.
Multi-AZ RDS instances are optional and have a cost associated with them. When creating your RDS instance, the user is asked if they would like to use a Multi-AZ RDS instance.
Read replicas
Read Replicas for MySQL, MariaDB, and PostgreSQL instances use the native, asynchronous replication functionality of their respective database engines.
Performance metrics and monitoring
Performance metrics for Amazon RDS are available from the AWS Management Console or the Amazon CloudWatch API. In December 2015, Amazon announced an optional enhanced monitoring feature that provides an expanded set of metrics for the MySQL, MariaDB, and Aurora database engines.
RDS Costs
Amazon RDS instances are priced very similarly to Amazon Elastic Compute Cloud (EC2). RDS is charged per hour and come in two packages: On-Demand DB Instances and Reserved DB Instances. On-Demand instances are at an ongoing hourly usage rate. Reserved DB Instances require an up-front, one-time fee and in turn provide a discount on the hourly usage charge for that instance.
Apart from the hourly cost of running the RDS instance, users are charged for the amount of storage provisioned, data transfers and Input and Output operations performed. AWS have introduced Provisioned Input and Output Operations, in which the user can define how many IO per second is required by their application. IOPS can contribute significant cost to the total cost of running the RDS instance.
Database instance types
As of July 2016, Amazon RDS supports 27 DB Instance Types, 18 of which are the latest generation, to support different types of workloads:
Competitors and alternatives
Several other vendors provide cloud database services similar to Amazon RDS. Oracle offers Oracle Cloud, a database service supporting Oracle's database technology. Microsoft offers Windows Azure SQL, a service supporting the Microsoft SQL database. Competitors supporting MySQL include RackSpace Cloud Databases , Google Cloud SQL, HP Cloud for MySQL, Xeround Cloud Database, and ClearDB.