The steps for launching, monitoring, and modifying burstable performance instances (T
instances) are similar. The key difference is the default credit specification when they
launch.
Each T instance family comes with the following
default credit specification:
-
T4g, T3a, and T3 instances launch as unlimited
-
T3 instances on a Dedicated Host can only launch as standard
-
T2 instances launch as standard
You can change the default credit specification for the account.
You can launch your T instances with a credit specification of unlimited
or standard
.
The following procedures describe how to use the EC2 console or the AWS CLI. For
information about using an Auto Scaling group, see Configure an Auto Scaling group to
set the credit specification as unlimited.
- Console
-
To configure the credit specification of an instance at launch
-
Follow the procedure to launch an instance.
-
Under Instance type, select a T instance
type.
-
Expand Advanced details. For Credit
specification, select a credit specification.
-
In the Summary panel, review your instance
configuration, and then choose Launch instance.
- AWS CLI
-
To set the credit specification of an instance at launch
Use the run-instances command with the
--credit-specification
option.
--credit-specification CpuCredits=unlimited
- PowerShell
-
To set the credit specification of an instance at launch
Use the New-EC2Instance
cmdlet with the -CreditSpecification_CpuCredit
parameter.
-CreditSpecification_CpuCredit unlimited
When T instances are launched or started, they require CPU credits for a good
bootstrapping experience. If you use an Auto Scaling group to launch your instances, we
recommend that you configure your instances as unlimited
. If you do, the
instances use surplus credits when they are automatically launched or restarted by the
Auto Scaling group. Using surplus credits prevents performance restrictions.
You must use a launch template for launching
instances as unlimited
in an Auto Scaling group. A launch configuration does not
support launching instances as unlimited
.
- Console
-
To create a launch template that sets the credit specification
-
Follow the Create a launch template using advanced settings procedure
in the Amazon EC2 Auto Scaling User Guide.
-
In Launch template contents, for
Instance type, choose an instance size.
-
To launch instances as unlimited
in an Auto Scaling group,
under Advanced details, for Credit
specification, choose
Unlimited.
-
When you've finished defining the launch template parameters,
choose Create launch template.
- AWS CLI
-
To create a launch template that sets the credit specification
Use the create-launch-template command.
aws ec2 create-launch-template \
--launch-template-name my-launch-template
\
--version-description FirstVersion
\
--launch-template-data CreditSpecification={CpuCredits=unlimited
}
- PowerShell
-
To create a launch template that sets the credit specification
Use the New-EC2LaunchTemplate
cmdlet. Define the credit specification for the launch template data as follows.
$creditSpec = New-Object Amazon.EC2.Model.CreditSpecificationRequest
$creditSpec.CpuCredits = "unlimited"
$launchTemplateData = New-Object Amazon.EC2.Model.RequestLaunchTemplateData
$launchTemplateData.CreditSpecification = $creditSpec
To associate the launch template with an Auto Scaling group, create the Auto Scaling group using
the launch template, or add the launch template to an existing Auto Scaling group.
- Console
-
To create an Auto Scaling group using a launch template
Open the Amazon EC2 console at
https://console.aws.amazon.com/ec2/.
-
On the navigation bar at the top of the screen, select the same
Region that you used when you created the launch template.
-
In the navigation pane, choose Auto Scaling Groups,
Create Auto Scaling group.
-
Choose Launch Template, select your launch
template, and then choose Next Step.
-
Complete the fields for the Auto Scaling group. When you've finished
reviewing your configuration settings on the Review
page, choose Create Auto Scaling
group. For more information, see Creating an Auto Scaling
Group Using a Launch Template in the
Amazon EC2 Auto Scaling User Guide.
To add a launch template to an existing Auto Scaling group
Open the Amazon EC2 console at
https://console.aws.amazon.com/ec2/.
-
On the navigation bar at the top of the screen, select the same
Region that you used when you created the launch template.
-
In the navigation pane, choose Auto Scaling
Groups.
-
From the Auto Scaling group list, select an Auto Scaling group, and choose
Actions, Edit.
-
On the Details tab, for Launch
Template, choose a launch template, and then choose
Save.
- AWS CLI
-
To create an Auto Scaling group using a launch template
Use the create-auto-scaling-group command and specify the
--launch-template
parameter.
To add a launch template to an existing Auto Scaling group
Use the update-auto-scaling-group command and specify the
--launch-template
parameter.
- PowerShell
-
To create an Auto Scaling group using a launch template
Use the New-ASAutoScalingGroup cmdlet and specify the
-LaunchTemplate_LaunchTemplateId
or
-LaunchTemplate_LaunchTemplateName
parameter.
To add a launch template to an existing Auto Scaling group
Use the Update-ASAutoScalingGroup cmdlet and specify the
-LaunchTemplate_LaunchTemplateId
or
-LaunchTemplate_LaunchTemplateName
parameter.
You can switch the credit specification of a running or stopped T instance at any
time between unlimited
and standard
.
Note that in unlimited
mode, an instance can spend surplus credits,
which might incur an additional charge. For more information, see Surplus credits can incur
charges.
- Console
-
To manage the credit specification of an instance
Open the Amazon EC2 console at
https://console.aws.amazon.com/ec2/.
-
In the left navigation pane, choose
Instances.
-
(Optional) Select an instance. On its Details
tab, find Credit specification. The value is either
unlimited
or standard
.
-
(Optional) To modify the credit specification for multiple
instances at the same time, select them all.
-
Choose Actions, Instance
settings, Change credit specification.
This option is enabled only if you selected a T instance.
-
For Unlimited mode, select or clear the
checkbox next to each instance ID.
- AWS CLI
-
To get the credit specification of an instance
Use the describe-instance-credit-specifications command. If you do not
specify an instance ID, all instances with the credit
specification of unlimited
are returned. The output would also
include instances that were previously configured with the unlimited
credit specification. For example, if you resize a T3 instance to an M4 instance,
while it is configured as unlimited
, Amazon EC2 returns the M4
instance.
aws ec2 describe-instance-credit-specifications \
--instance-id i-1234567890abcdef0
\
--query InstanceCreditSpecifications[].CpuCredits \
--output text
The following is example output.
unlimited
To set the credit specification of an instance
Use the modify-instance-credit-specification command.
aws ec2 modify-instance-credit-specification \
--region us-east-1
\
--instance-credit-specification "InstanceId=i-1234567890abcdef0
,CpuCredits=unlimited
"
- PowerShell
-
To get the credit specification of an instance
Use the Get-EC2CreditSpecification cmdlet.
(Get-EC2CreditSpecification `
-InstanceId i-1234567890abcdef0
).CpuCredits
The following is example output.
unlimited
To set the credit specification of an instance
Use the Edit-EC2InstanceCreditSpecification cmdlet.
Edit-EC2InstanceCreditSpecification `
-Region us-east-1
`
-InstanceCreditSpecification @({InstanceId="i-1234567890abcdef0
" CpuCredits="unlimited"})
Each T instance family comes with a default
credit specification. You can change the default credit specification for each
T instance family at the account level per AWS Region. The valid values for the
default credit specification are unlimited
and standard
.
If you use the launch instance wizard in the EC2 console to launch instances, the
value you select for the credit specification overrides the account-level default credit
specification. If you use the AWS CLI to launch instances, all new T instances in the
account launch using the default credit specification. The credit specification for
existing running or stopped instances is not affected.
Consideration
The default credit specification for an instance family can be modified only once
in a rolling 5-minute period, and up to four times in a rolling 24-hour
period.
- Console
-
To manage the default credit specification
Open the Amazon EC2 console at
https://console.aws.amazon.com/ec2/.
-
To change the AWS Region, use the Region selector in the upper-right corner of the page.
-
On the left navigation pane, choose EC2
Dashboard.
-
From Account attributes, choose Default
credit specification.
-
Choose Manage.
-
For each instance family, choose Unlimited or
Standard, and then choose
Update.
- AWS CLI
-
To get the default credit specification
Use the get-default-credit-specification command.
aws ec2 get-default-credit-specification \
--region us-east-1
\
--instance-family t2
\
--query InstanceFamilyCreditSpecifications[].CpuCredits \
--output text
The following is example output.
standard
To set the default credit specification
Use the modify-default-credit-specification command. The following
example sets the value to unlimited
.
aws ec2 modify-default-credit-specification \
--region us-east-1
\
--instance-family t2
\
--cpu-credits unlimited
- PowerShell
-
To get the default credit specification
Use the Get-EC2DefaultCreditSpecification cmdlet.
(Get-EC2DefaultCreditSpecification `
-Region us-east-1
`
-InstanceFamily t2
).CpuCredits
The following is example output.
standard
To set the default credit specification
Use the Edit-EC2DefaultCreditSpecification cmdlet. The following
example sets the value to unlimited
.
Edit-EC2DefaultCreditSpecification `
-Region us-east-1
`
-InstanceFamily t2
`
-CpuCredit unlimited