I don't understand the use for AWS EC2 and RDS as separate services. Is an EC2 instance a necessary prerequisite of launching an RDS instance? Can you have a database on your EC2 instance?
2 Answers
2
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RDS is a database-as-a-service; you don't know or care what it is running on, because you don't install it, manage it or perform any of the maintenance on the box it runs on (i.e. software updates). AWS takes care of all of that for you and simply charges you by the hour for using the service.
You can install SQL Server or MySQL (or any other database) on your own EC2 instance, but now its your responsibility to administer. Both are valid uses cases, but in general, for small databases, and especially for test and dev databases, I install SQL Server on my own EC2 instances and manage it myself to have flexibility and save money.
For larger, more critical and production databases, RDS is often a better choice - at a higher cost. The best scenario for you will depend on a lot of things (your budget, your skills, the need for high availability etc).
1
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You can install any databases on ec2 instance (whatever in windows or Linux). ec2 is a standalone virtual server with your fully control
But RDS service, you needn't care of the detail on how to install the database, set the environment, upgrade the version, backup/restore, multi-AZ setup, and so on, AWS RDS Service will take care all of them. Get it ready and you can immediately connect it and start your work. The way to provide RDS services are very similar as service elasticache (memcached & redis)
There is no require for you to launch a new ec2 instance for RDS service setup.
Don't mix ec2 and RDS. They are separate services.
Another way to make you understand this question is,
Amazon RDS is a Software as a Service (SaaS) that provides a full featured relational database service
