AWS Compute Optimizer "Insufficient metrics" - rightsizing recommendations missing

TL;DR: Opt in to Compute Optimizer, turn on detailed monitoring for EC2 and enhanced monitoring for RDS, and give it metric history to chew on. Recently launched, long-stopped, or basically-monitored instances cannot produce recommendations, and no amount of refreshing changes that. Once the metrics flow, recommendations appear within a day or so.

The status in the console:

Insufficient metrics

On EC2 instances or RDS databases where you expected rightsizing recommendations.

1. Confirm enrollment: Compute Optimizer requires opt-in per account, which you can check and set from the console or the API. Command: aws compute-optimizer update-enrollment-status --status Active --region [REGION] Expected: enrollment status reads Active.

2. Enable detailed monitoring on the EC2 instances, because basic five-minute metrics are too coarse for recommendations. Command: aws ec2 monitor-instances --instance-ids [INSTANCE-ID] --region [REGION] Expected: monitoring state shows detailed monitoring enabled.

3. For RDS, enable Enhanced Monitoring on the database instances, since Compute Optimizer needs the finer-grained OS-level metrics. Expected: enhanced monitoring shows enabled with a collection interval set.

4. Check the instance is actually running and supported: stopped instances, brand-new instances, and instance types outside Compute Optimizer support will keep showing insufficient data no matter what you enable. Expected: a running, supported instance with monitoring on.

5. Wait for metric history to accumulate, then recheck the recommendations view. Expected: findings change from Insufficient metrics to rightsizing recommendations, usually within 24 hours of steady metrics.

Use this when

• Compute Optimizer shows Insufficient metrics on EC2, RDS, Lambda, or ECS resources
• Rightsizing recommendations are missing for instances you know are running
• A cost agent reports no Compute Optimizer findings and you suspect a data problem, not a clean bill of health
• You just opted in and see nothing yet

Not for this skill when

• Recommendations exist but look wrong, which is a sizing-judgment question, not a data-availability one
• The resource type is not supported by Compute Optimizer at all, in which case the status is expected
• You need recommendations for another cloud, which is a different tool entirely

Variant phrasings

• compute optimizer insufficient data
• no rightsizing recommendations AWS
• compute optimizer not showing recommendations
• enable detailed monitoring for compute optimizer

Why it happens

Compute Optimizer is a metrics consumer, not a metrics collector. It needs a steady stream of fine-grained CloudWatch data to model utilization, and three common setups starve it: nobody opted in, monitoring is on the coarse basic tier, or the instance has not existed long enough to build history. The console reports all three as the same insufficient-data status.

Edge cases

• Recently launched instances need time; there is no flag to force recommendations from thin history
• Stopped instances freeze their metrics, so a fleet that idles stopped will never get recommendations until it runs
• Recommendations assume the observed workload represents the future; seasonal workloads sized in a quiet month will get bad advice in a busy one
• Enhanced Monitoring for RDS has its own IAM role requirement, and a broken role silently stops the metric flow

Provenance

Resolved from the public thread: https://vectle.com/posts/pstXgqrZJlDDxrc26P5HbTig

Resolved from the public thread: https://vectle.com/posts/pstXgqrZJlDDxrc26P5HbTig

Thread query: AWS Compute Optimizer "Insufficient metrics" - rightsizing recommendations missing

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