Monitors, troubleshoots, and manages GKE TPU Dynamic Slices custom resources. Use when checking TPU slice lifecycle states, troubleshooting slice provisioning failures, validating single-slice or multi-slice (JobSet) workload manifests, or safely patching stuck finalizers and disabling the slice controller. Don't use for generic GKE cluster node pool creation or standard non-TPU workload management (use gke-basics or gke-cluster-creation instead).
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Monitors, troubleshoots, and manages GKE TPU Dynamic Slices custom resources. Use when checking TPU slice lifecycle states, troubleshooting slice provisioning failures, validating single-slice or multi-slice (JobSet) workload manifests, or safely patching stuck finalizers and disabling the slice controller. Don't use for generic GKE cluster node pool creation or standard non-TPU workload management (use gke-basics or gke-cluster-creation instead).
Monitors the status of TPU Slice custom resources, troubleshoots provisioning failures, validates workload manifests on dynamic slices, and performs cleanups.
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kubectlgcloudGather project, cluster, and slice context using cluster tools or the following parameters:
{project_id} (e.g., my-gcp-project){cluster_name} (e.g., tpu-cluster){location} (e.g., us-central1-a){slice_name} (e.g., test-slice){timestamp} (Optional; default to the last 30 minutes
window [T - 30m] to [T + 30m])When asked to inspect, troubleshoot, or check a slice status, immediately execute kubectl describe slice {slice_name} using available cluster tools to perform the inspection. Parse the resulting Status.Conditions output against the condition table below to diagnose the exact state and provide concrete recommendations.
Command:
kubectl describe slice {slice_name}
Analyze the Status.Conditions (especially Type: Ready and its Reason and
Status):
| Lifecycle State / Reason | Meaning | Recommended Action |
|---|---|---|
SliceNotCreated | GKE Slice Controller is initializing the slice and performing resource checks. | Wait a few minutes and re-check slice status. |
SliceCreationFailed | Prerequisites validation failed (e.g., selected nodes don't exist, nodes are already used by another slice, or the topology doesn't match the number of partitions). | Verify selected nodes exist, are unallocated, and topology matches partition count. |
ACTIVATING | GKE is actively forming and provisioning the TPU slice. | Monitor node provisioning. |
ACTIVE | The TPU slice is successfully formed and ready to host workloads. | Proceed to deploy or check workloads. |
ACTIVE_DEGRADED | The slice is usable, but one or more sub-blocks are degraded. | Monitor workload logs for interconnect or device errors. Check faulty node VMs. |
FAILED | GKE failed to form the TPU slice (e.g., selected nodes are not part of the same reservation block). | Ensure all selected nodes belong to the same reservation block. |
DEACTIVATING | The slice is dismantling (triggered by user deletion or a critical systemic failure). | Wait for dismantling to finish, or patch finalizers if stuck. |
INCOMPLETE | The terminal phase before the Slice CR is deleted from the cluster. | No action required; the resource will be removed shortly. |
When investigating slice creation or provisioning failures (SliceCreationFailed or FAILED), perform the following verification steps:
kubectl get nodes -l cloud.google.com/gke-tpu-slice, kubectl get slice -A).2x2 requires 4 nodes).Ensure workload manifests are configured correctly to target the dynamic slice.
Check that the Pod template contains the following annotations and selectors:
cloud.google.com/gke-tpu-slice-topology: "{topology}" (e.g.,
"4x4x4")cloud.google.com/gke-tpu-topology: "{topology}" (e.g., "4x4x4")cloud.google.com/gke-tpu-accelerator: "{accelerator_type}" (e.g.,
"tpu7x")cloud.google.com/gke-tpu-slice: "{slice_name}" (e.g., "test-slice")If deploying a multi-slice JobSet, verify:
alpha.jobset.sigs.k8s.io/exclusive-topology: cloud.google.com/gke-tpu-slicecloud.google.com/gke-tpu-slice-topology: "{topology}"cloud.google.com/gke-tpu-topology: "{topology}"cloud.google.com/gke-tpu-accelerator: "{accelerator_type}"cloud.google.com/gke-tpu-slice in the
nodeSelector; JobSet handles slice assignment automatically.If a slice is stuck in DEACTIVATING or deletion hangs indefinitely due to stuck finalizers:
Identify Cause: Explain that finalizers on the slice resource (metadata.finalizers) are preventing Kubernetes from completing resource deletion.
Propose Resolution: Propose removing finalizers from the metadata path (/metadata/finalizers) using a JSON patch operation:
kubectl patch slice {slice_name} --type json -p='[{"op": "remove", "path": "/metadata/finalizers"}]'
Provide Warning: Explicitly warn the user that removing finalizers bypasses standard controller dismantling and may leave underlying VM, network, or accelerator resources uncleaned or orphaned.
CRITICAL SAFETY MANDATE: The response MUST explicitly ask the user for confirmation (e.g. "Removing finalizers on /metadata/finalizers via JSON patch is a high-risk operation that may leave orphaned resources. Do you confirm you want to apply this patch to slice {slice_name}?") and pause for user confirmation before applying or executing the patch.
If dynamic slicing needs to be disabled:
Check for existing Slices:
kubectl get slice -A
Ensure all slices are deleted before disabling the controller.
Disable Slice Controller via gcloud:
gcloud container clusters update {cluster_name} \
--location={location} \
--no-enable-slice-controller
Delete the Slice CRD:
kubectl delete crd slices.accelerator.gke.io
Clean up Node Labels: Remove GKE TPU Slice labels from all nodes in the cluster:
kubectl label nodes --all cloud.google.com/gke-tpu-slice- cloud.google.com/gke-tpu-slice-topology-
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