Intermittent External Network Connectivity Issues Affecting Build VMs
Postmortem
Minor impact
Updates
Postmortem
## Summary CI runners in the us-west1 and us-central1 regions intermittently experienced connection timeouts of approximately 134 seconds when reaching external services such as GitHub and Bitbucket over outbound network gateways. ## Impact * CI runners in the affected regions intermittently experienced connection timeouts of approximately 134 seconds when reaching external services \(e.g., GitHub, Bitbucket\) over our outbound network gateways. * The issue was intermittent rather than constant — connections succeeded under normal load, and failures clustered during periods of high outbound traffic volume. * No data was lost or corrupted. This was a network-connectivity and capacity issue, not a data-integrity issue. * us-west1 and us-central1 were the affected regions; other regions were not impacted by this issue. ## Root Cause Our load balancer distributes outbound traffic across multiple NAT gateways using a hashing method based on connection details \(source/destination address and port\). For any single connection, these details stay constant for that connection's lifetime. We had a sustainted traffic surge for a few seconds which congested the gateways ## Action Items To prevent such issues from happening again Harness will, Increase outbound connection capacity on our NAT gateways by provisioning additional external network interfaces, giving each gateway a substantially larger pool of connections it can serve concurrently..
Resolved
This incident has been resolved.
Monitoring
We are continuing to monitor for any further issues.
Monitoring
A fix has been implemented and we are monitoring the results.
Investigating
Summary - We are intermittently facing network connectivity issues with our Build VM's unable to connect to external resources. We are currently investigating the issue.