Cases2 cases

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1. IL-0237 A Kubernetes patch upgrade evicted every Ray Serve head and worker pod at once, and Lucidworks hosted LLMs went down

   Lucidworks2026sev1

   Symptoms

   From 16:18 UTC on 28 May 2026 the Lucidworks AI hosted LLMs in the us-southcarolina region were unavailable: queries to llama-3-8b-instruct, llama-3v2-3b-instruct and phi-4-multimodal-instruct returned 500 or 429 errors. Search, embedding models, the Lucidworks Platform UI and passthrough LLM calls kept working.

   Service outagePod evictionImage pull failures

   Trigger

   A routine Kubernetes patch upgrade on a cluster in us-southcarolina cycled its node pools one after another in quick succession.

   Root cause

   Faulty deployment

   Component

   Node poolModel inference server

   Contributing factor

   No staged rolloutOverlapping failures

   Remediation

   • Deleted the degraded replacement head node that could not pull container images
   • Waited for the LLM image pulls to finish on the replacement nodes
   • Launched new nodes with the required LLM images and redirected Lucidworks AI traffic to them

   Action items

   • Upgrade clusters that host LLM workloads in sequence, with each node pool fully healthy before the next one is upgraded
   • Investigate image pre-loading, such as pre-baked disks or image streaming, for large ML model images
   • Open a support ticket with the cloud provider about the abnormal Docker pull times
   • Coordinate Kubernetes maintenance windows with LLM service owners so they do not clash with ongoing deployments
   • Build tooling to force a Ray cluster failover to the blue or green state instead of waiting for Ray to settle it

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2. IL-0234 An onboarding operator deployed without its scope file installed dev applications on other IONOS Kubernetes clusters

   IONOS Cloud2026

   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.

   Control plane unresponsiveImage pull failures

   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

   Faulty deployment

   Component

   CI systemContainer registry and its credentials

   Contributing factor

   No configuration testsExcessive blast radiusMissed in review

   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.

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