General Information FAQ

What is Amazon RDS?

Amazon Relational Database Service (Amazon RDS) is a web service that makes it easy to set up, operate, and scale a relational database in the cloud. It provides cost-efficient and resizable capacity, while managing time-consuming database administration tasks, freeing you up to focus on your applications and business.

Amazon RDS gives you access to the capabilities of a familiar MySQL or Oracle database. This means that the code, applications, and tools you already use today with your existing MySQL databases should work seamlessly with Amazon RDS. Amazon RDS automatically patches the database software and backs up your database, storing the backups for a user-defined retention period. You benefit from the flexibility of being able to scale the compute resources or storage capacity associated with your relational database instance via a single API call or few clicks of the AWS Management Console. In addition, Amazon RDS makes it easy to use replication (currenly supported for MySQL only) to enhance database availability, improve data durability, or scale beyond the capacity constraints of a single database instance for read-heavy database workloads. As with all Amazon Web Services, there are no up-front investments required, and you pay only for the resources you use.

What is a database instance (DB Instance)?

You can think of a DB Instance as a database environment in the cloud with the compute and storage resources you specify. You can create and delete DB Instances, define/refine infrastructure attributes of your DB Instance(s), and control access and security via the AWS Management Console, Amazon RDS APIs, and Command Line Tools. Multiple MySQL databases or Oracle Database schemas can be created on a given DB Instance.

What does Amazon RDS manage on my behalf?

Amazon RDS manages the work involved in setting up a relational database, from provisioning the infrastructure capacity you request to installing the database software. Once your database is running on its own DB Instance, Amazon RDS automates common administrative tasks, such as performing backups and patching the database software that powers your DB Instance. For optional Multi-AZ deployments, Amazon RDS also manages synchronous data replication across Availability Zones and automatic failover.

Since Amazon RDS provides native database access, you interact with the relational database software as you normally would. This means you’re still responsible for managing the database settings that are specific to your application. You'll need to build the relational schema that best fits your use case and are responsible for any performance tuning to optimize your database for your application’s workflow.

When would I use Amazon RDS vs. Amazon EC2 Relational Database AMIs vs. Amazon SimpleDB?

Amazon Web Services provides a number of database alternatives for developers. Amazon RDS enables you to run a fully featured relational database while offloading database administration; Amazon SimpleDB provides simple index and query capabilities with seamless scalability; and using one of our many relational database AMIs on Amazon EC2 and Amazon EBS allows you to operate your own relational database in the cloud. There are important differences between these alternatives that may make one more appropriate for your use case. See Running Databases on AWS for guidance on which solution is best for you.

How do I get started with Amazon RDS?

To sign up for Amazon RDS, you must click the “Sign up for Amazon RDS” button on the Amazon RDS detail page and complete the sign-up process. You must have an Amazon Web Services account; if you do not already have one, you will be prompted to create one when you begin the Amazon RDS sign-up process. After you are signed up for RDS, please refer to the Amazon RDS documentation, which includes our Getting Started Guide.

How do I create a DB Instance?

DB Instances are simple to create, using either the AWS Management Console, Amazon RDS API, or command line interface (CLI). For information, see Creating and Modifying DB Instances

How do I access my running DB Instance?

Once your DB Instance is available, you can retrieve its endpoint via the DB Instance description in the AWS Management Console or DescribeDBInstance API. Using this endpoint you can construct the connection string required to connect directly with your DB Instance using your favorite database tool or programming language. In order to allow network requests to your running DB Instance, you will need to authorize access. For a detailed explanation of how to construct your connection string and get started, please refer to our Getting Started Guide.

How many DB Instances can I run with Amazon RDS?

By default, customers are allowed to have up to a total of 20 Amazon RDS DB instances. Of those 20, up to 10 can be Oracle DB Instances under the "License Included" model. All 20 can be used for MySQL or Oracle under the "BYOL" model. If your application requires more DB Instances, you can request additional DB Instances via this request form.

How do I import data to Amazon RDS?

There are a number of simple ways to import data into Amazon RDS, such as with the mysqldump or mysqlimport utilities for MySQL, and import/export or SQL Loader for Oracle. For more information on data import and export, please refer to the Amazon RDS Data Import Guide for MySQL or to the Amazon RDS Data Import Guide for Oracle.

Which relational database engines does Amazon RDS support?

Amazon RDS currently supports MySQL 5.1 and 5.5 (Community Edition) with InnoDB as the default database storage engine and Oracle Database 11gR2.

If you are using MySQL, you can use Amazon RDS MySQL DB Engine Version Management for optional control over the MySQL minor version of your DB Instance.

If you are using Oracle, you can use Amazon RDS Oracle DB Engine Version Management for optional control over the patch level of your DB Instance.

What storage engines does Amazon RDS for MySQL support?

The Point-In-Time-Restore and Snapshot Restore features of Amazon RDS for MySQL require a crash recoverable storage engine and are supported for InnoDB storage engine only. While MySQL supports multiple storage engines with varying capabilities, not all of them are optimized for crash recovery and data durability. For example, MyISAM storage engine does not support reliable crash recovery and may result in lost or corrupt data when MySQL is restarted after a crash, preventing Point-In-Time-Restore or Snapshot restore from working as intended. However, if you still choose to use MyISAM with Amazon RDS, following these steps may be helpful in certain scenarios for Snapshot Restore functionality.

If you would like to convert existing MyISAM tables to InnoDB tables, you can use the alter table command (e.g., alter table TABLE_NAME engine=innodb;). Please bear in mind that MyISAM and InnoDB have different strengths and weaknesses, so you should fully evaluate the impact of making this switch on your applications before doing so.

In addition, Federated Storage Engine is currently not supported by Amazon RDS for MySQL.

What is a maintenance window? Will my DB Instance be available during software maintenance?

You can think of the Amazon RDS maintenance window as an opportunity to control when DB Instance modifications (such as scaling DB Instance class) and software patching occur, in the event either are requested or required. If a “maintenance” event is scheduled for a given week, it will be initiated and completed at some point during the 30 minute maintenance window you identify.

The only maintenance events that require Amazon RDS to take your DB Instance offline are scale compute operations (which generally take only a few minutes from start-to-finish) or required software patching. Required patching is automatically scheduled only for patches that are security and durability related. Such patching occurs infrequently (typically once every few months) and should seldom require more than a fraction of your maintenance window. If you do not specify a preferred weekly maintenance window when creating your DB Instance, a 30 minute default value is assigned. If you wish to modify when maintenance is performed on your behalf, you can do so by modifying your DB Instance in the AWS Management Console or by using the ModifyDBInstance API. Each of your DB Instances can have different preferred maintenance windows, if you so choose.

Running your DB Instance as a Multi-AZ deployment can further reduce the impact of a maintenance event, as Amazon RDS will conduct maintenance via the following steps: 1) Perform maintenance on standby 2) Promote standby to primary 3) Perform maintenance on old primary, which becomes the new standby.

For more information on using the APIs or command line interface to specify your maintenance window, please refer to the Amazon RDS User Guide.

What should I do if my queries seem to be running slow?

If you are using MySQL, you can access the MySQL slow query logs for your database to determine if there are slow-running SQL queries and, if so, the performance characteristics of each. You could set the "slow_query_log" DB Parameter and query the mysql.slow_log table to review the slow-running SQL queries. Please refer to the Amazon RDS User Guide to learn more about working with DB Parameter Groups.

If you are using Oracle, you can use the Oracle trace file data to identify slow queries. For more information on accessing trace file data, please refer to the Amazon RDS User Guide.

You may also want to check the CPU utilization metrics for your DB Instance via Amazon CloudWatch. High levels of CPU utilization can reduce query performance and in this case you may want to consider scaling your DB Instance class. For more information on monitoring your CPU utilization, read the Amazon RDS Monitoring Guide.