         | Did this page help you? Yes No Tell us about it... |
Reserved Instances
You can use Amazon Elastic Compute Cloud (Amazon EC2) Reserved Instances to take advantage of elastic cloud computing while lowering costs and reserving capacity. With Reserved Instances, you pay a low, one-time fee to reserve capacity for a specific instance and get a significant discount on the hourly fee for that instance when you use it. Reserved Instances can provide substantial savings over owning your own hardware or running only On-Demand instances. At the same time, you know that the capacity you need is available to you when you require it.
![[Note]](http://docs.amazonwebservices.com/docs-common/images/note.png) | Note |
|---|---|
If you are using the Amazon Web Services (AWS) free usage tier to run Amazon EC2 instances, and then you purchase a Reserved Instance, you will be charged for the Reserved Instance under standard pricing guidelines. The AWS free usage tier is available for new AWS accounts. The free tier applies to certain participating AWS services up to a specific maximum amount of usage each month, for a period of a year. When an account goes over the usage limit for a free tier, the standard AWS service rates will be billed to your credit card. For information about the free tier and the applicable services and usage amounts, go to AWS Free Usage Tier. |
Reserved Instances are available in three varieties—Heavy Utilization, Medium Utilization, and Light Utilization—that enable you to optimize your Amazon EC2 costs based on your expected utilization. You can start lowering your costs today by matching your application's usage pattern with the pricing model that works best for you.
To purchase an Amazon EC2 Reserved Instance, you must select an instance type (such as m1.small), platform (Linux/UNIX, Windows, Windows with SQL Server, or SUSE), location (Region and Availability Zone), and term (either one year or three years). If you want to use Amazon Virtual Private Cloud (Amazon VPC), you must specify that you want your capacity reservation allocated to Amazon VPC.
If you're using Amazon VPC, you must select a platform that includes Amazon VPC in its name. You can also choose to purchase Reserved Instances that are physically isolated at the host hardware level by specifying Dedicated as the instance tenancy. For more information about Dedicated Instances, go to Using EC2 Dedicated Instances Within Your VPC in the Amazon Virtual Private Cloud User Guide.
These sections describe Reserved Instance basics:
To understand consolidated billing and how the pricing benefit of Reserved Instances is applied, see Understanding the Pricing Benefit and Consolidated Billing.
To understand Reserved Instance Pricing Tiers and how to take advantage of the discount pricing, see Understanding Reserved Instance Pricing Tiers.
If you want to get started with Reserved Instances, see Working with Reserved Instances.
Reserved Instances Offerings
You can choose a Reserved Instance type based on how you plan to utilize your instance. You can pick the fee structure that fits your needs.
Starting with API version 2011-11-01, you can choose from a variety of Reserved Instance offerings that address your projected utilization of the instance: Heavy Utilization, Medium Utilization, and Light Utilization.
Heavy Utilization Reserved Instances enable workloads that have a consistent baseline of capacity or run steady-state workloads. Heavy Utilization Reserved Instances require the highest upfront commitment, but if you plan to run more than 79 percent of the Reserved Instance term you can earn the largest savings (up to 58 percent off of the On-Demand price). Unlike the other Reserved Instances, with Heavy Utilization Reserved Instances, you pay a one-time fee, followed by a lower hourly fee for the duration of the term regardless of whether or not your instance is running.
Medium Utilization Reserved Instances are the best option if you plan to leverage your Reserved Instances a substantial amount of the time, but want either a lower one-time fee or the flexibility to stop paying for your instance when you shut it off. This offering type is equivalent to the Reserved Instance offering available before API version 2011-11-01. Medium Utilization Reserved Instances are a more cost-effective option when you plan to run more than 40 percent of the Reserved Instance term. This option can save you up to 49 percent off of the On-Demand price. With Medium Utilization Reserved Instances, you pay a slightly higher one-time fee than with Light Utilization Reserved Instances, and you receive lower hourly usage rates when you run an instance.
Light Utilization Reserved Instances are ideal for periodic workloads that run only a couple of hours a day or a few days per week. Some of these use cases, such as disaster recovery, also require reserved capacity to meet potential demand without notice. Using Light Utilization Reserved Instances, you pay a one-time fee followed by a discounted hourly usage fee when your instance is running. You can start saving when your instance is running more than 17 percent of the Reserved Instance term, and you can save up to 33 percent off of the On-Demand rates over the entire term of your Reserved Instance.
Remember that discounted usage fees for Reserved Instance purchases are tied to instance type and Availability Zone. If you shut down a running EC2 instance on which you have been getting a discounted rate as a result of a Reserved Instance purchase, and the term of the Reserved Instance has not yet expired, you will continue to get the discounted rate if you launch another instance with the same specifications during the term.
The following table summarizes the differences between the Reserved Instances offering types.
Reserved Instance Offerings
| Offering | Upfront Cost | Usage Fee | Advantage |
|---|---|---|---|
|
Heavy Utilization |
Highest |
Lowest hourly fee. Applied to the whole term whether or not you're using the Reserved Instance. |
Lowest overall cost if you plan to utilize your Reserved Instances more than 76 percent of a 3-year term. |
|
Medium Utilization |
Average |
Hourly usage fee charged for each hour you use the instance. We encourage you to turn off your instances when you aren't using them so you won't be charged for them. |
Suitable for elastic workloads or when you expect moderate usage, more than 44 percent of a 3-year term. |
|
Light Utilization |
Lowest |
Hourly usage fee charged. Highest fees of all the offering types, but they apply only when you're using the Reserved Instance. We strongly encourage you to turn off your instances when you aren't using them so you won't be charged for them. |
Highest overall cost if you plan to run all of the time, however lowest overall cost if you anticipate you will use your Reserved Instances infrequently, more than about 8 percent of a 3-year term. |
Checklist for Finding, Purchasing, Verifying, and Running Reserved Instances
The following list describes the process for using Reserved Instances. You can use the AWS Management Console, the Command Line Tools, or the API to perform any of these tasks.
Specify the details about the Reserved Instance you want to launch.
The platform on which to run your instance.
The instance type of the instance.
The term (time period) over which you want to hold the instance.
The tenancy specification, if you want to reserve capacity for your instance to run in single-tenant hardware.
The region and Availability Zone where you want to run the instance.
Choose the offering type that addresses your cost and payment needs.
Heavy Utilization
Medium Utilization
Light Utilization
For more information about these offering types, see Reserved Instances Offerings.
Search for offerings that meet the criteria you specified.
If you want to use a Reserved Instance with Amazon Virtual Private Cloud (Amazon VPC), make sure to search for and select an offering that includes Amazon VPC in the description.
Purchase offerings that fulfill your requirements.
Run your Reserved Instance by launching an instance with the criteria you specified when you purchased your Reserved Instance. These criteria include platform, instance type, region, and Availability Zone.
Confirm that your instances are running as specified.
Note If your Reserved Instance purchase crosses from one pricing tier to another, your new purchase will go into a pending state while the Reserved Instance service processes the purchase. Processing involves purchasing two or more different Reserved Instances for you: An amount at one tier, and an amount at the next tier which would be either the discounted rate or the higher discounted rate. As a result, the Reserved Instance ID returned by your purchase CLI command and API action will be different from the actual ID of the new Reserved Instances. For more information, see Understanding Reserved Instance Pricing Tiers.
If you are new to Reserved Instances, and you want to learn about the tools need to work with Reserved Instances, see Tools and Prerequisites.
To get started finding and purchasing your Reserved Instance, see Working with Reserved Instances.
