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1. IL-0464 IONOS Managed Kubernetes control planes went unreachable for minutes at a time as their shared etcd grew and fragmented

   IONOS Cloud2026

   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.

   Control plane unresponsiveImage pull failures

   Root cause

   Capacity exhaustion

   Component

   etcdKubernetes API serverManaged Kubernetes control plane and provider API

   Contributing factor

   Excessive blast radius

   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

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2. IL-0152 An incorrect configuration applied during maintenance made an internal infrastructure cluster automatically delete the control planes of 200 DOKS clusters in FRA1

   DigitalOcean2024

   Symptoms

   At 13:02 UTC on 2024-01-23 DigitalOcean posted that, as of 12:18 UTC, its engineers were investigating an issue with Kubernetes clusters in the FRA1 region and that users might see errors when communicating with their clusters. The control planes of the affected DOKS (DigitalOcean Kubernetes) clusters had become inaccessible.

   Resources deletedControl plane unresponsive

   Trigger

   An incorrect configuration was applied to an internal infrastructure cluster in FRA1 at 12:21 UTC during a maintenance operation.

   Root cause

   Configuration change

   Component

   etcdKubernetes API server

   Contributing factor

   Automation amplificationNo safeguard on destructive changeExcessive blast radius

   Detection

   Engineers were investigating errors with Kubernetes clusters in FRA1 as of 12:18 UTC and identified the incorrect configuration as the cause at 12:36.

   Remediation

   • restored each affected cluster's etcd from its latest twice-daily backup
   • restored the stateless control plane components after etcd
   • patched the recovery mechanism after unexpected problems during recovery
   • found and fixed an additional small bug during recovery
   • contacted affected customers directly with further instructions, since some might need to reconfigure Kubernetes resources

   Action items

   • Prevent automatic deletion of infrastructure cluster resources under any circumstances in the production environment

   Lessons

   When managed control planes run as resources in another cluster, one configuration mistake in that cluster can delete hundreds of control planes at once through ordinary automation. The etcd backups limited the damage, but their twice-daily schedule set the worst case at 12 hours of lost control plane state, and the recovery tooling itself needed patching during the incident.

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