Elastic Compute Cloud

TL;DR
Burstable instances
Disks
Further readings
1. Sources

TL;DR

Use an instance profile to pass an IAM role to an EC2 instance.

T instances launch as unlimited by default. Launch them in standard mode to avoid paying for surplus credits.

The instance type can be changed. The procedure depends on the root volume, but does require downtime.

Real world use cases

# Get the IDs of running nginx instances in 'dev'.
aws ec2 describe-instances --output 'text' \
  --query 'Reservations[].Instances[].InstanceId[]'
  --filters \
    'Name=instance-state-name,Values=running' \
    'Name=tag:env,Values=dev' \
    'Name=tag:app,Values=nginx' \

# Start SSM sessions to specific machines.
aws ec2 describe-instances --output text \
  --query 'Reservations[].Instances[].InstanceId' \
  --filters \
    'Name=app,Values=mysql' \
    'Name=instance-state-name,Values=running' \
| xargs -ot aws ssm start-session --target

# Show images details.
aws ec2 describe-images --image-ids 'ami-8b8c57f8'
aws ec2 describe-images --filters \
  'Name=name,Values=["al2023-ami-minimal-*"]' \
  'Name=owner-alias,Values=["amazon"]' \
  'Name=architecture,Values=["arm64","x86_64"]' \
  'Name=block-device-mapping.volume-type,Values=["gp3"]'

# Describe security groups.
aws ec2 describe-security-groups --group-names 'pulumi-workshop'

# Delete security groups.
aws ec2 delete-security-group --group-name 'pulumi-workshop'
aws ec2 delete-security-group --group-id 'sg-0773aa724d0c2dd51'

# Query the onboard IMDSv1 metadata server.
curl 'http://instance-data/latest/meta-data/instance-id'
curl 'http://169.254.169.254/latest/meta-data/instance-type'
curl 'http://[fd00:ec2::254]/latest/meta-data/local-ipv4'

Burstable instances

T instances are burstable.

Refer Burstable performance instances and Key concepts and definitions for burstable performance instances.

Traditional EC2 instance types provide fixed CPU resources.
Burstable performance instances provide a baseline level of CPU utilization, with the ability to burst CPU utilization above the baseline level.

One only pays for the baseline CPU, plus any additional burst CPU usage over a 24-hour period.

The baseline utilization and ability to burst are governed by CPU credits.
Burstable performance instances continuously earn credits when they stays below the CPU baseline, and continuously spend credits when they bursts above the baseline.
Accrued credits can be used later to burst above baseline CPU utilization.
Credits can be accrued only up to a point. How high this limit is depends on the instance type.
When the credits spent are more than credits earned, the instance behavior depends on the credit configuration mode (Standard or Unlimited).

In Standard mode, burstable instances:

Use the accrued credits to burst above baseline CPU utilization when they are available.
Gradually come down to baseline CPU utilization if there are no accrued credits remaining.
Cannot burst above baseline until they accrue more credits.

In Unlimited mode, burstable instances:

Use the accrued credits to burst above baseline CPU utilization when they are available.
Spend surplus credits to continue bursting above baseline if there are no accrued credits remaining.
Use CPU credits they earn to pay down the surplus credits they spent earlier when CPU utilization falls below the baseline again.

The ability to earn CPU credits to pay down surplus credits is what enables EC2 to average the CPU utilization of instances over a 24-hour period.
If the average CPU usage over a 24-hour period exceeds the baseline, instances are billed for the additional usage at a flat additional rate per vCPU-hour.

Disks

See EBS.

6.5 KiB Raw Blame History

Elastic Compute Cloud

TL;DR

Burstable instances

Disks

Further readings

Sources

6.5 KiB

Raw Blame History