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 as unlimited
or standard
using the Amazon EC2 console, an AWS SDK, a command line tool, or with an Auto Scaling
group.
The following procedures describe how to use the EC2 console or the AWS CLI. For
information about using an Auto Scaling group, see Use an Auto Scaling group to
launch a burstable performance instance as Unlimited.
- Console
-
To launch a T instance as Unlimited or Standard
-
Follow the procedure to launch an instance.
-
Under Instance type, select a T instance
type.
-
Expand Advanced details, and for Credit
specification, select a credit specification. If you do not
make a selection, the default is used, which is standard
for
T2, and unlimited
for T4g, T3a and T3.
-
In the Summary panel, review your instance
configuration, and then choose Launch instance. For
more information, see Launch an Amazon EC2 instance using the launch
instance wizard in the Amazon EC2 console.
- AWS CLI
-
To launch a T instance as Unlimited or
Standard
Use the run-instances command to launch your instances. Specify the
credit specification using the --credit-specification
CpuCredits=
parameter. Valid credit specifications are
unlimited
and standard
.
-
For T4g, T3a and T3, if you do not
include the --credit-specification
parameter, the instance
launches as unlimited
by default.
-
For T2, if you do not include the --credit-specification
parameter, the instance launches as standard
by
default.
aws ec2 run-instances \
--image-id ami-abc12345
\
--count 1
\
--instance-type t3.micro
\
--key-name MyKeyPair
\
--credit-specification "CpuCredits=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
.
unlimited
mode is not supported for T3 instances that are launched
on a Dedicated Host.
- Console
-
To create a launch template that launches instances as
Unlimited
-
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 launches instances as
Unlimited
Use the create-launch-template command and specify
unlimited
as the credit specification.
-
For T4g, T3a and T3, if you do not
include the CreditSpecification={CpuCredits=unlimited}
value, the instance launches as unlimited
by
default.
-
For T2, if you do not include the
CreditSpecification={CpuCredits=unlimited}
value, the
instance launches as standard
by default.
aws ec2 create-launch-template \
--launch-template-name MyLaunchTemplate
\
--version-description FirstVersion
\
--launch-template-data ImageId=ami-8c1be5f6
,InstanceType=t3.medium
,CreditSpecification={CpuCredits=unlimited
}
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.
- AWS CLI
-
To create an Auto Scaling group using a launch template
Use the create-auto-scaling-group AWS CLI command and specify the
--launch-template
parameter.
- Console
-
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 add a launch template to an existing Auto Scaling group
Use the update-auto-scaling-group AWS CLI command and specify the
--launch-template
parameter.
You can view the credit specification (unlimited
or
standard
) of a running or stopped T instance.
- Console
-
To view the credit specification of a T instance
Open the Amazon EC2 console at
https://console.aws.amazon.com/ec2/.
-
In the left navigation pane, choose
Instances.
-
Select the instance.
-
Choose Details and view the Credit
specification field. The value is either
unlimited
or standard
.
- AWS CLI
-
To describe the credit specification of a T instance
Use the describe-instance-credit-specifications command. If you do not
specify one or more instance IDs, all instances with the credit
specification of unlimited
are returned, as well as 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
Example output
{
"InstanceCreditSpecifications": [
{
"InstanceId": "i-1234567890abcdef0",
"CpuCredits": "unlimited"
}
]
}
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 modify the credit specification of a T instance
Open the Amazon EC2 console at
https://console.aws.amazon.com/ec2/.
-
In the left navigation pane, choose
Instances.
-
Select the instance. To modify the credit specification for several
instances at one time, select all applicable instances.
-
Choose Actions, Instance
settings, Change credit specification.
This option is enabled only if you selected a T instance.
-
To change the credit specification to unlimited
, select
the check box next to the instance ID. To change the credit specification
to standard
, clear the check box next to the instance
ID.
- AWS CLI
-
To modify the credit specification of a T instance
Use the modify-instance-credit-specification command. Specify the
instance and its credit specification using the
--instance-credit-specification
parameter. Valid credit
specifications are unlimited
and standard
.
aws ec2 modify-instance-credit-specification \
--region us-east-1
\
--instance-credit-specification "InstanceId=i-1234567890abcdef0
,CpuCredits=unlimited
"
Example output
{
"SuccessfulInstanceCreditSpecifications": [
{
"InstanceId": "i- 1234567890abcdef0"
}
],
"UnsuccessfulInstanceCreditSpecifications": []
}
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.
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 set the default credit specification at the account level per
Region
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 set the default credit specification at the account level
(AWS CLI)
Use the modify-default-credit-specification command. Specify the AWS
Region, instance family, and the default credit specification using the
--cpu-credits
parameter. Valid default credit specifications
are unlimited
and standard
.
aws ec2 modify-default-credit-specification \
--region us-east-1
\
--instance-family t2
\
--cpu-credits unlimited
You can view the default credit specification of a T instance family at the account
level per AWS Region.
- Console
-
To view the default credit specification at the account level
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.
- AWS CLI
-
To view the default credit specification at the account level
Use the get-default-credit-specification command. Specify the AWS
Region and instance family.
aws ec2 get-default-credit-specification --region us-east-1
--instance-family t2