I've got a pair of related news items for users of the Amazon Relational Database System (RDS):
- We now support version 5.1.49 of MySQL, with the InnoDB Plugin as the InnoDB storage engine.
- We now provide a new, optional level of control over when and if your DB Instance(s) are upgraded to new MySQL versions supported by Amazon RDS. This new functionality is called DB Engine Version Management, and this post will help you understand what it can do and how to use it.
MySQL Version 5.1.49 with InnoDB Plugin
Version 5.1.49 of MySQL includes a number of bug fixes and enhancements. For DB Instances running MySQL 5.1.49, the most significant change is the inclusion of InnoDB Plugin as the InnoDB storage engine, replacing InnoDB Builtin. InnoDB Plugin offers (according to the feature page) performance and scalability enhancements (especially on multi-core platforms), fast index creation, data compression, and more. The InnoDB Builtin (InnoBase) is not available in 5.1.49 and will not be available in future Amazon RDS Supported versions.
New DB Instances that you create will now run MySQL 5.1.49 with InnoDB Plugin, unless otherwise specified using the new DB Engine Version Management feature described in the next section.
DB Engine Version Management
With DB Engine Version Management, Amazon RDS gives you additional (yet optional) control over the version of relational database software (i.e. MySQL) powering your DB Instance. The goal of this functionality is to provide you the flexibility to maintain compatibility with specific MySQL versions, test new versions with your application before deploying in production, and perform version upgrades on your own terms and timelines. Let’s take a look:
DB Instance Creation
Amazon RDS now allows you to create new DB Instances using any supported version of MySQL. Right now this means version 5.1.45 and 5.1.49, but we plan to support additional minor and major versions (e.g. MySQL 5.5) in the future. There's a new EngineVersion attribute associated with each DB Instance, and you can specify your desired Version when issuing a CreateDBInstance API call (or the associated command). New DB Instances will now use MySQL 5.1.49 with InnoDB Plugin by default. If you still wish to use MySQL 5.1.45 (which uses InnoDB Builtin) for a new DB Instance, you can do so using this new functionality.
Automatic Upgrade Schedule
Your existing DB Instances will be upgraded to the new version of MySQL with InnoDB Plugin during your scheduled maintenance window on the week of October 4, 2010. If you don't want to upgrade, you need to use ModifyDBInstance to set the AutoMinorVersionUpgrade attribute of your DB instances to "false."
Find Your Engine
The new DescribeDBEngineVersions API call returns a list of all supported versions of MySQL. You can use it (or the rds-describe-db-engine-versions command) to drive your configuration process. You could also use it to set up a really cool automated testing framework. You could call the function, iterate through the resulting list of versions, and create a new DB Instance for each one. Then you could test your application to make sure that it works with each version of MySQL. Or you could create several DB Instances (one per version) simultaneously and test the same queries against each instance.
Choose to Upgrade Today
With DB Engine Version Management, you can also upgrade any of your existing DB Instances to InnoDB Plugin and the new version of MySQL today by setting the EngineVersion attribute to "5.1.49" using the ModifyDBInstance API call (or the associated command). Amazon RDS will take care of the rest. This will happen immediately if you set the ApplyImmediately flag when you modify the EngineVersion attribute, or at the next maintenance window for your DB Instance if you don't.
To learn more about DB Engine Version Management and associated API changes, please visit our Forum Post on the subject. You can also read more about the new functionality via our DB Engine Version Management FAQs, which include information about our guidelines for supporting new versions and deprecating old versions.
With these changes, Amazon RDS becomes even more powerful. If you want to verify that your application works with the new version of MySQL, simply create a snapshot of your existing DB Instance, create a new one from the snapshot, and test away.