Incident date: September 1, 2026
Duration: Approximately 90 minutes
Affected service: Sigma organizations hosted in Google Cloud Platform (GCP) us-central1

Summary

On September 1, a Google Cloud networking incident in part of the us-central1 region interrupted connectivity to Sigma services. Customers hosted in GCP us-central1 were unable to reliably access the Sigma application, administration UI, workbooks, and some embedded experiences. No Sigma code or configuration change triggered the incident.

Root cause

During routine maintenance, Google Cloud experienced a network failure in part of the us-central1-b zone. Sigma services in the region had a non-redundant network dependency in the affected zone, so a zone-scoped failure caused a broader service disruption for customers hosted in the region. See the Google Cloud incident report for details about the cloud provider event.

Resolution

Google Cloud restored the underlying network service, and Sigma recovered without a Sigma-side deployment. Customers did not need to make changes to resume using Sigma.

Corrective actions

Sigma is taking the following actions:

• Increase network redundancy across affected Sigma services in this region. Other regions are not impacted by the same deficiency as that in us-central1.
• Add additional production health monitoring that operates independently of the environment it monitors.
• Improve zone-level availability monitoring and alerting for external status pages.
• Improve retry and recovery behavior for background workloads (including materialization) during transient network failures.

We apologize for the disruption and are using this incident to improve the resilience and independent detection of Sigma services.