Check CPU credits on AWS t2 instances

Published on Author Artem ButusovLeave a comment

t2 instances and gentoo

AWS t2 instances could be a bad choice for compilation of heavy application, especially on Gentoo without binary repo. Before upgrading any heavy package like gcc, glibc, kernel it is good to check if your instance has enough CPU credits to compile package without falling back to baseline performance.

You could read more about t2 instance here:

script to check cpu credits

You could easily check CPU credits with small bash script below:


CPU_CREDITS_WARN=50 # in percents


metadata="$(curl -sL" 
region=$(echo "$metadata" | jq -r .region)
instance_id=$(echo "$metadata" | jq -r .instanceId)
instance_type=$(echo "$metadata" | jq -r .instanceType)

start_time=$(date -u -d "10 minutes ago" +%Y-%m-%dT%H:%M:%S)
end_time=$(date -u +%Y-%m-%dT%H:%M:%S)

    aws cloudwatch get-metric-statistics \
        --namespace AWS/EC2 \
        --region ${region} \
        --metric-name CPUCreditBalance \
        --start-time "${start_time}" \
        --end-time "${end_time}" \
        --period 60 \
        --statistics Average \
        --dimensions Name=InstanceId,Value="${instance_id}" \
    | jq -r '.Datapoints[] | .["Average", "Timestamp"]' | tail -n 2

cpu_credits_value=$(echo "$cpu_credits_metadata" | head -n 1)
cpu_credits_ts=$(echo "$cpu_credits_metadata" | tail -n 1)
cpu_credits_ratio=$(echo "$cpu_credits_value / $cpu_credits_max * 100" | bc -l)
cpu_credits_warn=$(echo "$cpu_credits_ratio <= $CPU_CREDITS_WARN" | bc -l)

echo "Instance ID: $instance_id"
echo "Instance Type: $instance_type"
echo "Region ID: $region"
echo "Timestamp: $cpu_credits_ts"
echo "CPU Credits: $(printf %.0f $cpu_credits_value) / $(printf %.0f $cpu_credits_max) ($(printf %.0f $cpu_credits_ratio)%)"

exit $cpu_credits_warn

script dependencies

Please note, this script depends on bash, jq and aws:

  • bash is preinstalled
  • jq could be installed with emerge jq
  • aws could be installed with emerge awscli

aws configuration

aws requires configuration on instance where you will use it. You could follow official article:

You will also need to grant read access to your user access for cloudwatch.CPUCreditBalance metric thru AWS console.

Your policy could look like (where A.B.C.D is ip address of your instance):

    "Version": "2012-10-17",
    "Statement": [
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": "cloudwatch:GetMetricStatistics",
            "Resource": "*",
            "Condition": {
                "IpAddress": {
                    "aws:SourceIp": "A.B.C.D/32"


  • log into aws console
  • create user
  • remember Access Key ID and Secret Access Key
  • add inline policy
  • log into instance and configure aws

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