Amazon Discounts Cloud Relational Database Service

Amazon is offering reserved instances of its cloud-based relational database service. Reserved instance is a new form of pricing for cloud computing that exchanges upfront payments to the supplier for guaranteed availability of service and lower hourly rates over a one- to three-year period.

The Amazon Web Services unit launched the reserved instances approach for its EC2 cloud servers in March 2009.

The relational database service (RDS) is an EC2 offering that makes a version of the popular MySQL 5.1 database available to remote users. Through the management console offered by AWS, customers may select a size of database instance, reserve storage for its data output, and launch a system. Existing MySQL applications can be run on the system, making it a popular option.

A small instance of RDS on EC2 is currently listed at $0.11 an hour. If used continuously over the course of year, that would result in a charge of $2.64 a day or $963.60 a year. Under the RDS reserved instances approach, a customer could use a small database system for a year with an upfront payment of $227.50 plus $.046 cents an hour for each hour of actual use.

If the reserved instance database system was restricted by its owner to use only during the eight-hour work day, that usage would result in a year's hourly charge of $134.32. Combined with the $227.50 upfront payment, the charge for a year's use would only be $361.82. Making the reserved instance available 16 hours a day would increase the charge to $496.14. Making it available 24 hours a day would result in a combined charge of $630.46, or about one-third off the regular hourly price over a year of $963.60.

The discount is larger when a reserved instance is contracted for on a three-year basis: a 46% discount off the regular hourly rate, Amazon officials said, in making the announcement

Thus reserved instances offer an incentive to customers to bring a regular workload into the cloud. They have a secondary effect of making Amazon's capacity planning task a little simpler through the long term commitment.

Database instances come in small, large, extra large, extra large with high memory, and double extra large with high memory sizes, under the Amazon plan. There's even a quadruple extra large, which if rented on an hourly basis, would cost $3.10 an hour versus the 11 cents for the basic instance. As the database instances move up the price list, they come equipped with more CPU horsepower and memory.

MySQL tools, such as a query building tool, will work with the Amazon RDS version of MySQL as well as existing applications, Amazon spokesmen said.