Summary
Between approximately 11:37 AM and 3:01 PM PDT (18:37–22:01 UTC) on September 29, 2026, customers using Harness CI self-hosted Linux cloud runners in prod1/prod2 (us-west1) experienced intermittent networking failures during pipeline execution — primarily Git/network timeouts when fetching source code.
Root Cause
This was primarily due to saturation of our NAT which was futher exacerbated by a temporary cloud provider compute capacity, preventing new VM provisioning there.
Impact
- Customers running self-hosted Linux CI builds in us-west1 saw intermittent build/pipeline failures, not a full outage.
- Observed customer-facing errors included Git fetch timeouts, e.g.
Failed to connect to github.com port 443: Connection timed out
Remediation
-
Immediate: Rebalanced ARM build-VM load from the saturated us-west1 path toward central1 (partially limited by central1 capacity); restarted the affected Cloud NAT gateways, which stabilized pipeline networking.
Action Items
- Secure additional NAT gateway/IP capacity (In progress)
- Improve NAT saturation detection and alerting ahead of customer impact.
- Evaluate cross-region capacity contingencies so a single region's compute shortage doesn't block failover mitigation.