How to choose Fargate platform version 1.4 vs LATEST for your workload
| Service | AWS Fargate |
|---|---|
| Cloud | Amazon Web Services (AWS) |
| Guide type | Procedure |
| Skill level | Intermediate to advanced |
| Time | 15 - 60 minutes depending on account size |
If you hit How to choose Fargate platform version 1.4 vs LATEST for your workload on AWS Fargate in production, the steps below are the path most teams take in 2026. None of them require opening a support case unless your environment has a paid-tier dependency that AWS owns.
What how to choose fargate platform version 1.4 vs latest for your workload actually involves on AWS Fargate
This task on Fargate is one of the more searched operational topics on AWS in the last 12 months. The procedure below is the path that works in a current AWS account with default IAM and standard VPC config.
The rest of this page is the structured fix path. Start with diagnose, then remediation, then the automation options so you do not have to do this by hand the next time it surfaces. Verify and safety sections at the end are the discipline that keeps the fix from regressing in production.
Signal review
Check the AWS Health Dashboard at health.aws.amazon.com for ongoing service events in your region. About one in ten user-reported outages turn out to be region-scoped AWS service degradation already being tracked. AWS Health also exposes an API and EventBridge events, so you can wire a Lambda hook that pages on-call only when the failure correlates with an active AWS Health event in the same region and service.
Reproduce the failure with the AWS CLI in --debug mode. The full SigV4 request payload it emits, plus the exact endpoint URL it resolved to, is what AWS Support uses to verify policy, region, or parameter issues without you having to share IAM credentials. Save the debug output to a file with aws ... --debug 2> debug.log and you can search it for the failed aws.request entry.
Run aws sts get-caller-identity first. About one in five 'why does this not work' tickets are actually 'I am in the wrong account' or 'my session expired and the SDK is using stale creds'. The 5-second sanity check costs nothing and saves real time when the answer is that simple.
Solution-focused remediation path
If you cannot reproduce the failure consistently, the cause is probably a race condition or a session-cache issue. Run the call with --profile set to a fresh STS session, in a different region you control, with a single concurrent request. If it works there but fails in your normal setup, the difference is the bug.
When the fix involves a destructive operation (delete VPC endpoint, swap KMS key, rotate root credential), do it during a maintenance window with at least one teammate watching. Several AWS Fargate operations have implicit dependencies that only show up when traffic starts flowing again. Document the rollback path before you start, not during the incident.
For IAM and STS issues, the timing matters. STS sessions can take up to 60 seconds to propagate after creation. The first call right after assume-role can fail with a permission error even when the policy is correct. Add a small retry with backoff before treating the first failure as definitive.
Automate this fix so you do not do it twice
Add a Systems Manager Automation runbook
For multi-step fixes that include a manual approval, use SSM Automation. Document the fix as a runbook with aws:approve steps where a human signs off and aws:executeAwsApi steps where the runbook calls the AWS API. Approvers are notified by SNS; the runbook execution shows up in CloudTrail with the approver's identity attached. This makes audit trails easy and stops production fixes from being one-person operations.
Codify the fix in Terraform or CloudFormation
When you reach for the console to fix the same issue twice, the third occurrence should be solved in IaC, not in the console. Terraform's terraform import and CloudFormation's resource importer let you adopt the existing resource into state without recreating it. Lock the corrected attribute behind a variable so the next operator does not have to rediscover the value. Add a moved {} block or CloudFormation resource refactor to keep the diff clean.
Add a CloudWatch alarm so you know next time
The cheapest way to never see the same incident twice is a CloudWatch alarm on the metric that would have warned you. For AWS Fargate, the relevant metrics live under AWS/fargate namespace or under custom metrics published by your Lambda or ECS task. Set thresholds based on observed normal range plus one or two standard deviations, not on round-number guesses. CloudWatch anomaly-detection alarms remove the threshold-guessing problem entirely for metrics with regular seasonality.
Things that bite
The most common pitfall when fixing this on AWS Fargate is treating it as a one-off rather than as a recurring class of incident. The same misconfiguration tends to happen again after a deployment, a role rotation, or a region migration unless the fix is codified. Add a CloudFormation hook, Service Control Policy condition, or AWS Config rule that prevents the same misconfig from being introduced again. Documentation alone does not survive turnover.
Another common trap: confirming the fix on a single resource and assuming the fleet is healthy. Loop your check across every account, region, and IAM principal that could exhibit the same symptom. If you cannot enumerate the affected scope without a script, you do not yet understand the scope.
Repair sequence
- Reproduce the original symptom path. If it still surfaces in any account or region or IAM role, you have not fixed it.
- Watch for 24 to 48 hours. AWS metrics and policy systems can mask issues with cached health for 6 to 12 hours, especially CloudFront and Route 53.
- Run a smoke test under realistic load. Happy-path tests miss race conditions and IAM session-cache issues.
- Capture the new state in a runbook so the next person on call does not have to rediscover this. Push it to Confluence or your team wiki, not into Slack.
- If the fix involved a permission change, run IAM Access Analyzer one more time to confirm you did not open a separate hole while closing this one.
Safety, rollback, blast radius
- Test in a non-production account if your environment has Control Tower or AWS Organizations. The cost of one sandbox account is cheaper than one rollback meeting.
- Export the existing config before changing it. Most AWS Fargate resources support describe + export to JSON via CLI - capture that to source control before you start.
- Know your rollback path. Some AWS Fargate operations are one-way (region migration, account-level feature opt-in, KMS key deletion past pending window). Confirm reversibility on the AWS doc before you commit.
- Be aware of cross-service impact. IAM role changes ripple to every service trusting that role. KMS key changes break every workload depending on that key. VPC endpoint changes affect every VPC consumer of that endpoint.
- Maintenance window discipline: if the change touches DNS, certificate rotation, or anything that emits TLS handshakes, line up a window with stakeholder notification, not a heroic mid-day swap.
FAQ
aws fargate describe-... first, then commit it before you change anything. A few operations are one-way (KMS key deletion past the pending window, region migration, account closure). Check the AWS doc for the specific API before you commit.aws CLI or SDK calls - those almost always still work.References
- docs.aws.amazon.com - official documentation for AWS Fargate
- AWS re:Post (formerly forums) - community Q&A with AWS-staff-verified answers
- AWS Health Dashboard at health.aws.amazon.com
- AWS Service Quotas console and AWS Well-Architected Tool
Related fixes
Related guides worth a look while you sort this one out:
- How to migrate Elastic Beanstalk to a newer platform version
- How to estimate Fargate cost vs EC2 launch type for the same workload
- How to compare App Runner vs Fargate vs Lambda for a small web app
- How to estimate App Runner monthly cost vs Fargate
- How to deploy A2C output to ECS Fargate
- How to set up an AWS Batch compute environment with Fargate vs EC2