RESOURCE_IN_USE_BY_ANOTHER_RESOURCE on VPC. what causes it and how to fix
| Service | Google VPC |
|---|---|
| Cloud | Google Cloud (GCP) |
| Guide type | Procedure |
| Skill level | Intermediate to advanced |
| Time | 15 - 60 minutes depending on account size |
RESOURCE_IN_USE_BY_ANOTHER_RESOURCE on VPC, what causes it and how to fix on Google VPC sits in the most-reported issues list across r/aws, Google Cloud Community, and StackOverflow. The recovery path is mostly known, the Google Cloud docs just bury it under three layers of conceptual material.
What resource_in_use_by_another_resource on vpc, what causes it and how to fix actually involves on Google VPC
The RESOURCE_IN_USE_BY_ANOTHER_RESOURCE error from AWS typically surfaces with the message "RESOURCE_IN_USE_BY_ANOTHER_RESOURCE". The error code itself is what you grep for in AWS re:Post or in AWS Support cases, not the human-readable line.
On VPC, this most often comes from one of three causes: a missing or restrictive IAM permission, a service-level limit you have hit, or a transient AWS-side capacity issue. The fix path differs by which.
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.
Diagnose first, fix second
Run gcloud auth list and gcloud config list 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 credentials or ADC pointed at the wrong project'. The 5-second sanity check costs nothing and saves real time when the answer is that simple.
Reproduce the failure with the gcloud CLI in --debug mode. The full SigV4 request payload it emits, plus the exact endpoint URL it resolved to, is what Google Cloud Support uses to verify policy, region, or parameter issues without you having to share IAM credentials. Save the debug output to a file with gcloud ... --debug 2> debug.log and you can search it for the failed aws.request entry.
Check the Google Cloud Service Health at status.cloud.google.com and the per-product status board for ongoing service events in your region. About one in ten user-reported outages turn out to be region-scoped Google Cloud service degradation already being tracked. Cloud Service Health also exposes an API and Eventarc events, so you can wire a Lambda hook that pages on-call only when the failure correlates with an active Cloud Service Health event in the same region and service.
Solution-focused remediation path
If networking is suspect, use Network Intelligence Connectivity Tests. It is the only tool that simulates the full ENI-to-ENI path including firewall rules, hierarchical firewall policies, routes, and VPC Service Controls perimeters in one call. Manual trace is slower and misses transitive issues. The analyzer charges $0.10 per analysis - cheaper than a 30-minute call with your network team.
When the failure happens in production but not in dev, do not just compare the IAM policy. Compare the Org Policy / RCP at the OU level, the permission boundary on the role, and the resource-based policy on the target. One of those is almost always different between accounts. Policy Intelligence recommendations bundles make this comparison routine.
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.
Automate this fix so you do not do it twice
Add a Workflows or Cloud Tasks Automation runbook
For multi-step fixes that include a manual approval, use Workflows runbook. Document the fix as a runbook with workflows.executions.approve steps where a human signs off and workflows.steps.callApi steps where the runbook calls the Google Cloud API. Approvers are notified by SNS; the runbook execution shows up in Cloud Audit Logs with the approver's identity attached. This makes audit trails easy and stops production fixes from being one-person operations.
Automate the fix with the gcloud CLI
The CLI one-liner pattern for Google VPC operations is roughly: gcloud google describe RESOURCE --format=json --filter ... to read state, gcloud google update RESOURCE --quiet to apply the change, and gcloud google describe RESOURCE --format=json --filter ... again to verify. Wrap it in a shell script that sets a region variable at the top and exits on first error with set -euo pipefail so a partial run does not leave the account in a half-fixed state.
# Template - replace placeholders with your account specifics
export GOOGLE_CLOUD_REGION=us-central1
export GOOGLE_CLOUD_PROJECT=prod-project
gcloud google describe RESOURCE --format=json --filter 'Resources[?Status==`FAILED`].[Id,Reason]' --output table
gcloud google modify-... --resource-id RESOURCE_ID --no-dry-run
gcloud google describe RESOURCE_ID --query 'Status'Wire the fix into Eventarc for self-healing
If the failure mode is recurring, automate the remediation instead of the diagnosis. Eventarc Scheduler or rules that watch Cloud Logging events for the specific error code can invoke a Lambda that runs the same fix you would run by hand. The Lambda must be idempotent (re-running it on already-healthy resources must be a no-op) and must emit a Cloud Monitoring metric so you can track how often the auto-fix fires. A spike in auto-fix invocations is itself a signal worth alerting on.
# Eventarc rule pattern (JSON)
{ "source": ["aws.google"], "detail-type": ["Google Cloud API Call via Cloud Audit Logs"], "detail": { "errorCode": ["AccessDenied", "ThrottlingException"] }
}
Common pitfalls and what to watch for
The pitfall most teams hit on Google VPC is moving too fast and skipping the read-only validation step. Before any write, list the current state and save it. Google Cloud APIs are eventually consistent for many resource types, so the validation snapshot is your only reliable reference if you need to undo. Save the output of the describe call to S3, not to your laptop.
Second pitfall: confusing IAM permission errors with networking errors. AccessDenied can be IAM (policy missing), networking (VPC endpoint policy blocking the call), or KMS (key policy missing). The error string looks identical for all three. Distinguish by looking at the Cloud Audit Log event's errorCode and the encoded authorization message; do not assume IAM is the culprit just because the message says AccessDenied.
Verify the fix worked
- Reproduce the original symptom path. If it still surfaces in any account or region or IAM role or service account, you have not fixed it.
- Watch for 24 to 48 hours. Cloud Monitoring metrics and Cloud Asset Inventory can mask issues with cached health for 6 to 12 hours, especially Cloud CDN and Cloud DNS.
- 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 Resource Manager and Organization Policy or Cloud Resource Manager (organizations, folders, projects). The cost of one sandbox account is cheaper than one rollback meeting.
- Export the existing config before changing it. Most Google VPC resources support describe + export to JSON via CLI - capture that to source control before you start.
- Know your rollback path. Some Google VPC operations are one-way (region migration, account-level feature opt-in, Cloud KMS key deletion past pending window). Confirm reversibility on the Google Cloud doc before you commit.
- Be aware of cross-service impact. IAM role or service account changes ripple to every service trusting that role. Cloud 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
gcloud google describe-... first, then commit it before you change anything. A few operations are one-way (Cloud KMS key deletion past the pending window, region migration, account closure). Check the Google Cloud doc for the specific API before you commit.aws CLI or SDK calls - those almost always still work.References
- docs.cloud.google.com - official documentation for Google VPC
- Google Cloud Community - community Q&A with Google-staff-verified answers
- Cloud Service Health Dashboard at health.cloud.google.com
- Quotas page in Cloud Console (IAM & Admin > Quotas) and Architecture Framework checklists
Related fixes
Related guides worth a look while you sort this one out:
- RESOURCE_IN_USE_BY_ANOTHER_RESOURCE on Compute Engine, what causes it and how to fix
- RESOURCE_IN_USE_BY_ANOTHER_RESOURCE on Persistent Disk: what causes it and how to fix
- Fix RESOURCE_IN_USE_BY_ANOTHER_RESOURCE when deleting a VPC or subnet
- violationReason RESTRICTED_BY_EGRESS_POLICY on VPC Service Controls. what causes it and how to fix
- violationReason RESTRICTED_BY_INGRESS_POLICY on VPC Service Controls. what causes it and how to fix
- denied requested access to the resource is denied on Artifact Registry: what causes it and how to fix