EC2 Reserved Instance Expiring
CostLens flags active EC2 Reserved Instances expiring within 90 days, so you can renew before the covered usage reverts to on-demand pricing.
When a Reserved Instance lapses, the usage it covered silently falls back to on-demand rates (40–72% more expensive) with no warning — a budget surprise. CostLens flags active RIs nearing expiry so you can renew, modify, or plan ahead while the discount is still in place.
How it works
CostLens lists active Reserved Instances
Calls ec2:DescribeReservedInstances in each region (RIs are regional).
Computes time to expiry
For each active RI, calculates days until the end date and skips already-expired ones.
Flags RIs expiring within 90 days
Severity by urgency: high ≤30 days, medium ≤60 days, low ≤90 days.
Estimates the discount at risk
Estimates the monthly saving the RI currently provides (on-demand vs. RI rate × count) — the spend that returns to on-demand if you don't renew.
What to do
- Open the recommendation to see the instance type, count, and exact expiry date.
- Decide whether the workload is still steady-state — if so, renew or buy a replacement RI (or a Savings Plan) before expiry.
- This check is advisory — RI purchases are made in the AWS console or via Commitments.
Severity reflects urgency, not size
Unlike most checks, severity here is driven by how soon the RI expires, so you can triage by deadline.
Required IAM permissions
Read-only — covered by the CostLens ReadOnlyAccess policy from AWS Accounts:
ec2:DescribeReservedInstances
Limitations
- Advisory only — CostLens does not auto-renew or purchase Reserved Instances.
- Savings are an estimate based on current on-demand pricing for the instance type.