Cases3 cases

1 to 3 of 3

1. IL-0158 An expired credential caused authentication failures that stopped LKE and LKE-E from deploying clusters and nodes in all regions, which also blocked node recycling and cluster autoscaling

   Linode2026

   Symptoms

   From 11:45 UTC on 16 April 2026, customers of Linode Kubernetes Engine (LKE) and Linode Kubernetes Engine Enterprise (LKE-E) could not deploy new clusters or add new nodes to existing clusters. Because no new node could be deployed, node recycling and cluster autoscaling did not work either. The problem hit every region where LKE runs.

   Deploys failingScale-up failureCredentials unavailable

   Trigger

   A credential expired, which caused authentication failures when LKE and LKE-E deployed clusters and nodes. One status update describes it as an expired certificate.

   Root cause

   Certificate or credential expiry

   Component

   Node pool

   Contributing factor

   –

   Detection

   The first status page update, saying the team was investigating an emerging issue affecting LKE and LKE-E in all regions, was posted at 13:20 UTC.

   Remediation

   • created new credentials and deployed them, rotating the expired credential (certificate)

   Action items

   • Investigate what led to the credential expiry and take preventive actions

   Lessons

   One expired credential stopped every operation that needs a new node, in all regions at once: new clusters, added nodes, node recycling and autoscaling.

   View case
2. IL-0113 The managed GKE control plane of Webhook Relay's main cluster failed because its API server certificates had never been rotated, and a manual credential rotation reported success without taking effect

   Webhook Relay2022

   Symptoms

   At 12:00 EST the health check system reported that the backend APIs, the frontend and the tunnels in the EU region were down. The team first took it for a transient error, such as an interrupted client request or a server evicted for memory or CPU pressure, but the main dashboard was offline as well.

   Service outageControl plane lagControl plane unresponsiveStale or inconsistent API readsCredentials unavailable

   Root cause

   Certificate or credential expiry

   Component

   GKE control planeKubernetes API serverNode poolRBAC and service accounts

   Contributing factor

   Limited debug accessSingle point of failure

   Detection

   The health check system sent a notification that the service was down; the team then found the main dashboard offline.

   Remediation

   • recreated the node pools by hand after the credential rotation failed to recreate them
   • duplicated the main cluster's services into a newly created GKE cluster
   • deleted the Kubernetes Service records in the old cluster so its load balancers could be attached to the new cluster
   • detached the StatefulSet from the old cluster and switched all writes to the main disk
   • exported the data from the temporary ClickHouse instance and inserted it into the main instance

   Action items

   • Change the deployment manifests so services can be switched between clusters quickly without a complicated persistent disk migration

   Lessons

   Recovery of existing infrastructure needs a time limit. Throughout the outage the old cluster looked about to recover, and the reluctance to give up on the salvage effort kept the team from starting over with a new cluster much sooner, which would have been the right call. On older GKE clusters, check the validity of the cluster CA certificate, for example by decoding masterAuth.clusterCaCertificate from gcloud container clusters describe and reading it with openssl x509. GKE's multiple availability zones made no difference in this failure.

   View case
3. IL-0521 AKS pods could not mount volumes and new nodes got no CNI network interface after the cluster service principal expired

   Jenkins project2021

   Symptoms

   From 18:02 UTC on 2 June 2021, the Jenkins infrastructure AKS cluster logged errors about pods that were unable to mount volumes and about scaled-up nodes that were unable to obtain a network virtual interface from the CNI.

   Credentials unavailablePods stuck in ContainerCreating

   Trigger

   The Azure Service Principal credential of the AKS cluster expired at 17:53 UTC on 2 June 2021.

   Root cause

   Certificate or credential expiry

   Component

   Cluster cloud identityPersistent volumes and stateful setsCNI pluginNode pool

   Contributing factor

   Monitoring blind spot

   Detection

   The error behind the failures was found in the AKS UI console while the team investigated the root cause of the LTS 2.289.1 release problem.

   Remediation

   • Renewed the AKS cluster's Azure Service Principal credential, which made AKS restart all nodes automatically

   Action items

   • Add an automatic PagerDuty check that alerts a week before the service principal expires, as is done for certificates
   • Keep a team-level calendar for manual operations such as resetting a credential
   • Consider managed identities, which renew automatically, instead of the service principal

   View case

By root cause1