Purchasing On-Demand Instances for Amazon EC2
With On-Demand Instances, you pay for compute capacity by the second with no long-term commitments. You have full control over the instance's lifecycle—you decide when to launch, stop, hibernate, start, reboot, or terminate it.
There is no long-term commitment required when you purchase On-Demand Instances. You pay only for the
seconds that your On-Demand Instances are in the running state, with a 60-second minimum.
The price per second for a running On-Demand Instance is fixed, and is listed on the Amazon EC2 Pricing, On-Demand
Pricing page
We recommend that you use On-Demand Instances for applications with short-term, irregular workloads that cannot be interrupted.
For significant savings over On-Demand Instances, use AWS Savings Plans
Contents
On-Demand Instance quotas
There are quotas for the number of running On-Demand Instances per AWS account per Region. On-Demand Instance quotas are managed in terms of the number of virtual central processing units (vCPUs) that your running On-Demand Instances are using, regardless of the instance type. Each quota type specifies the maximum number of vCPUs for one or more instance families.
Your account includes the following quotas for On-Demand Instances. Instances that are in the pending, stopping, stopped, and hibernated states do not count towards your On-Demand Instance quotas. Capacity Reservations count toward your On-Demand Instance quotas, even if they are unused.
| Name | Default | Adjustable |
|---|---|---|
| Running On-Demand DL instances | 0 | Yes |
| Running On-Demand F instances | 0 | Yes |
| Running On-Demand G and VT instances | 0 | Yes |
| Running On-Demand HPC instances | 0 | Yes |
| Running On-Demand High Memory instances | 0 | Yes |
| Running On-Demand Inf instances | 0 | Yes |
| Running On-Demand P instances | 0 | Yes |
| Running On-Demand Standard (A, C, D, H, I, M, R, T, Z) instances | 5 | Yes |
| Running On-Demand Trn instances | 0 | Yes |
| Running On-Demand X instances | 0 | Yes |
For information about the different instance families, generations, and sizes, see the Amazon EC2 Instance Types Guide.
You can launch any combination of instance types that meet your changing application
needs, as long as the number of vCPUs does not exceed your account quota. For example,
with a Standard instance quota of 256 vCPUs, you could launch 32 m5.2xlarge
instances (32 x 8 vCPUs) or 16 c5.4xlarge instances (16 x 16 vCPUs). For
more information, see EC2 On-Demand Instance limits
Monitor On-Demand Instance quotas and usage
You can view and manage your On-Demand Instance quotas for each Region using the following methods.
To view your current quotas using the Service Quotas console
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Open the Service Quotas console at https://console.aws.amazon.com/servicequotas/home/services/ec2/quotas/
. -
From the navigation bar, select a Region.
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In the filter field, enter
On-Demand. -
The Applied quota value column displays the maximum number of vCPUs for each On-Demand Instance quota type for your account.
To view your current quotas using the AWS Trusted Advisor console
Open Service limits page
To configure CloudWatch alarms
With Amazon CloudWatch metrics integration, you can monitor your EC2 usage against your quotas. You can also configure alarms to warn about approaching quotas. For more information, see Service Quotas and Amazon CloudWatch alarms in the Service Quotas User Guide.
Request a quota increase
Even though Amazon EC2 automatically increases your On-Demand Instance quotas based on your usage, you can request a quota increase if necessary. For example, if you intend to launch more instances than your current quota allows, you can request a quota increase by using the Service Quotas console described in Amazon EC2 service quotas.
Query the prices of On-Demand Instances
You can use the Price List Service API or the AWS Price List API to query the prices of On-Demand Instances. For more information, see Using the AWS Price List API in the AWS Billing User Guide.
