Fly.io Upstash Redis Service Distruption

Postmortem

Critical impact

Started

Lasted 3h 59m

View official incident ↗

Updates

  1. Postmortem

    On May 12th and 13th at various times, a subset of Upstash Redis instances on [Fly.io](http://Fly.io) experienced intermittent hangs and elevated error rates. The Redis process would stall inside a logging syscall — alive but not making progress — which made the issue hard to spot from our usual telemetry. After investigating with Fly's team, we identified the root cause as a bad interaction between a recent guest kernel update on Fly's newer machines and an upstream Cloud Hypervisor bug \([cloud-hypervisor#7672](https://github.com/cloud-hypervisor/cloud-hypervisor/issues/7672)\) affecting log writes from inside the VM. We mitigated by disabling the affected logging paths, and Fly has since rolled out a hypervisor-side patch, fully resolving the issue. No data was lost. Sorry for the disruption.

  2. Resolved

    This incident has been resolved.

  3. Monitoring

    A fix has been implemented and we are monitoring the results.

  4. Identified

    The issue has been identified and the fix is being implemented.

  5. Investigating

    Some regions are experiencing connectivity issues due to an ongoing network problem. We are currently investigating