Incident Library
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  • Root cause
  • Component
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  • Contributing factor
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Cases2 cases

1 to 2 of 2

  1. Symptoms

    From 14 to 16 March 2026 a subset of customer control planes on IONOS Managed Kubernetes (MK8s) became unavailable again and again, each time for several minutes. While a cluster was unreachable, operations that depend on the Kubernetes API, such as deployments, scaling and health checks, did not work reliably.

    Root cause
    Component
    Contributing factor
    Remediation
    • Defragmented the affected database instances, reclaiming about 3–4 GiB per instance
    • Shortened the database compaction intervals on the affected instances
    • Deployed a fix for the affected AI Model Hub database services
    • Applied final changes to all affected clusters
    Action items
    • Expand monitoring dashboards to show control plane health per database instance
    • Move the highest-volume clusters to dedicated database backends
    • Make incidents of this kind trigger immediate paging
    • Roll the updated compaction interval out to all shared control plane database instances
    • Run automated, scheduled defragmentation jobs on all instances
    • Rebalance clusters across database instances to reduce concentration
    • Contact customers whose clusters write disproportionate data, for example to store large security scan reports outside the control plane database
    • Introduce per-tenant resource quotas and key-count limits on the shared control plane database
    • Re-architect the shared control plane for stronger isolation, with dedicated database instances and better vertical scaling
    • Evaluate full database sharding for customers with consistently high data volumes
    • Hold regular drills on database resource exhaustion and recovery
  2. Symptoms

    On 18 October 2024, from 7:50 to 8:01 UTC, about 25% of the hypervisors in Scaleway's FR-PAR-1 availability zone lost VPC connectivity with the rest of the region, and products that use VPC failed with them. Public internet connectivity and Elastic Metal VPC connectivity were not affected.

    Trigger

    At 6:20 UTC a Top of Rack switch in FR-PAR-1 had a software crash. One of the two BGP route reflectors for VPC ran on a hypervisor in that rack and was left in an abnormal state.

    Root cause
    Component
    Contributing factor
    Detection

    Health-check monitoring on both route reflectors detected the anomaly, and the Scaleway Customer Excellence and SRE teams detected the customer impact and opened an incident.

    Remediation
    • Fixed both VPC route reflectors by manual action
    Action items
    • Fixed the autohealing mechanism that had failed to fix route reflectors stuck in a stale state; the fix is https://github.com/FRRouting/frr/pull/17163
    • Run different software versions on the route reflectors so a single bug cannot stop several instances
    • Investigate the software issue that left the route reflectors in a stale state
Check your cluster for this

These 2 cases involve Managed Kubernetes control plane and provider API and BGP routing. 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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