Incident Library
  • Root cause
  • Component
  • Symptom
  • Contributing factor
  • Case

Cases2 cases

1 to 2 of 2

  1. Symptoms

    From 15:05 UTC on 6 August 2026 GitHub Actions workflow runs failed to start, failed partway through or stayed queued for a long time, on both GitHub-hosted and self-hosted runners. Some requests to the Actions REST API returned errors, and some customers saw unexpected rate limiting in their workflows.

    Trigger

    A routine deployment to an internal Actions service that processes events and generates Actions jobs replaced pods, and the remaining capacity became saturated.

    Root cause
    Component
    Contributing factor
    Remediation
    • Expanded capacity of the affected services
    • Throttled incoming webhook-triggered work
    • Increased processing capacity for the backlog of affected events
    • Deployed changes that stopped runners from repeatedly trying to acquire invalid jobs
    • Deployed a fix for self-hosted runners that were not picking up jobs and enabled it incrementally
    • Paused migrations with GitHub Enterprise Importer
    • Restored webhook-triggered Actions workflows to full throughput
    • Rolled back the mitigation that left some ARC runners offline, and recovered those runners by hand
    • Shared CLI and UI steps for customers to clear jobs that could not be retried or canceled
    Action items
    • Improve deployment and capacity safeguards for the affected services
    • Strengthen monitoring for the conditions that preceded the incident
    • Improve the resiliency and recovery of queued work and runner assignment
    • Add automatic recovery for self-hosted runners in upcoming Runner and ARC releases
    • Reduce the risk of cascading failures and speed up recovery during large Actions disruptions
  2. Symptoms

    On 8 May 2026 IONOS Cloud reported "K8s Control Planes not available": some Managed Kubernetes customers in DE/TXL, DE/FRA and DE/FRA/2 had trouble connecting to the control plane and saw degraded Kubernetes functionality. Between 15:22 and 16:12 (UTC+2) applications meant for a new internal development cluster were installed on other customer clusters, which were also modified.

    Trigger

    A routine internal operation onboarded a new Managed Kubernetes development cluster. The scoping configuration file for the onboarding operator failed to reach the deployment branch because of a merge conflict, and at the same time a second change removed the operator from the exclusion list, which deployed it at once.

    Root cause
    Component
    Contributing factor
    Remediation
    • Corrected the onboarding operator so it needs an explicit namespace configuration before acting on any cluster
    • Reconfigured the deployment system to fail deployments when required configuration files are missing
    • Rolled back the identified changes on the affected resources
    • Ran a recovery script, validated in staging, that removed all unintended installations and updates from the affected clusters
    Action items
    • Add a mandatory CI/CD step that confirms all required configuration files reached the target branch before any deployment starts
    • Require additional peer review and change management approval for every deployment that touches production, whatever its size
    • Give teams a way to inform each affected customer in time about the status of post-incident cleanup
    Lessons

    IONOS treats the unintended change to cluster configurations as a failure of the controls that should keep internal operations from affecting customer environments.

Check your cluster for this

These 2 cases involve CI system and Container registry and its credentials. kubegap audits a Kubernetes cluster for gaps like these, read-only, from Claude Code or Codex; its checks cite public reports like the ones in this library.

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