CostLensIdle Forwarding Rule (GCP)

Idle Forwarding Rule (GCP)

CostLens finds GCP load-balancer forwarding rules whose backend service has no backends — billing the per-rule hourly rate while serving nothing.

Updated July 20261 min read

CostLens finds idle GCP forwarding rules — load-balancer forwarding rules pointing at a backend service that has no backends. The rule still bills the per-rule hourly rate while routing no traffic, a common leftover after backends are removed but the load balancer front-end is left behind.

Deletion is irreversible

Deleting a forwarding rule removes that load-balancer front-end (and its IP binding). CostLens treats this as an irreversible action. Keep it if a deployment is about to attach backends.

How it works

Forwarding rules are enumerated

CostLens lists forwarding rules across regions via the Compute aggregated API.

Backend service is inspected

For each rule targeting a backend service, CostLens reads that service and checks whether it has any backends.

Empty rules are flagged

Rules whose backend service has zero backends are surfaced, priced at the forwarding-rule hourly rate.

What to do

  1. Confirm no deployment is about to attach backends (instance groups / NEGs) to the load balancer.
  2. Delete the forwarding rule (and the empty backend service / load balancer) in the Cloud Console to stop the charge.

Severity levels

SeverityEstimated monthly savings
critical>$500
high$100–$500
medium$20–$100
low<$20

Required permissions

  • Detect: Compute read (roles/compute.viewer or the read scope) — see GCP Accounts.

Limitations

  • Only rules that target a backend service are evaluated; target-pool and target-proxy chains are not flagged in this check.
  • A rule kept intentionally as a placeholder for an imminent deployment will still be flagged — review before deleting.
CostLens
Previous
Idle Static IP Address
CostLens
Next
Bucket Lifecycle Policy