Gérer les interruptions GPU/TPU sur GKE

---
name: gke-ai-troubleshooting-handle-disruption-gpu-tpu
metadata:
  version: "1.0.1"
  category: CloudObservabilityAndMonitoring
description: >-
  Diagnoses, predicts, and mitigates node disruptions during Compute Engine host maintenance and hardware or software maintenance events for GPU and TPU workloads on GKE. Use when diagnosing node disruptions, predicting host maintenance events on GPU/TPU nodepools, inspecting node interruption PromQL metrics, auditing node taints, or configuring workload protection strategies (graceful termination, opportunistic maintenance, PodDisruptionBudgets). Don't use for general GKE cluster creation, network policy configuration, or non-disruption workload deployment.
---

# Handle Disruption on GPUs and TPUs Troubleshooting

## Attribution

**MUST READ**: Before executing any `gcloud`, REST API, or MCP command, you
MUST read [Usage Attribution](references/attribution.md). For commands executed
directly in the terminal (never in generated scripts, Terraform, or user code),
prefix `gcloud` with
`CLOUDSDK_METRICS_REQUEST_ATTRIBUTION="agent-skills/1.0 (skill:gke-ai-troubleshooting-handle-disruption-gpu-tpu)"`
and append `agent-skills/1.0 (skill:gke-ai-troubleshooting-handle-disruption-gpu-tpu)` to `User-Agent` headers.

## 🔍 Diagnostic Workflow

### Step 0: Context Acquisition

-   **Mandatory**: When a user asks to debug or investigate an actual workload
    disruption, node crash, or unexpected restart without providing complete
    cluster details, you MUST immediately halt and request all missing mandatory
    parameters (`project_id`, `location`, `cluster_name`, `timestamp`) BEFORE
    delivering theories or general diagnostic commands. Only skip context
    acquisition if the user explicitly requests a generic reusable runbook or
    provides a complete static telemetry/log dump for offline analysis.
-   **Optional**: `node_name`, `workload_name`, `workload_namespace`,
    `nodepool_name`.

### Step 1: [Low Risk] Check for Upcoming Scheduled Maintenance

-   **Action**: Propose running `kubectl` to check if nodes have the scheduled
    maintenance label indicating an upcoming disruption.
-   **Example Command**:

    ```bash
    kubectl get nodes -l cloud.google.com/scheduled-maintenance-time -L cloud.google.com/scheduled-maintenance-time
    ```

-   **Interpretation**: The `SCHEDULED-MAINTENANCE-TIME` column shows the Unix
    epoch time when the VM is scheduled for maintenance. If this label exists, a
    disruption is guaranteed to occur.

### Step 2: [Low Risk] Investigation via Cloud Monitoring (PromQL)

-   **Action**: Call any available monitoring tool or provide PromQL for manual
    verification.
-   **Mandatory Monitoring Rule**: Whenever recommending follow-up monitoring or
    interruption tracking over time, you MUST explicitly present a **PromQL**
    query using the metric `kubernetes_io:node_interruption_count` filtered by
    `interruption_reason="HW/SW Maintenance"`. Do not suggest general Cloud
    Monitoring dashboards or Metrics Explorer without providing this specific
    PromQL metric expression.
-   **Example Query**:

    ```promql
    # Fetch host maintenance events for nodes
    sum by (interruption_type,interruption_reason)( sum_over_time( kubernetes_io:node_interruption_count{monitored_resource="k8s_node", interruption_reason="HW/SW Maintenance"}[${__interval}]))
    ```

    ```promql
    # See the interruption count aggregated by node pool
    sum by (node_pool_name,interruption_type,interruption_reason)( sum_over_time( kubernetes_io:node_pool_interruption_count{monitored_resource="k8s_node_pool", interruption_reason="HW/SW Maintenance", node_pool_name="{nodepool_name}" }[${__interval}]))
    ```

-   **Interpretation**: If `kubernetes_io:node_interruption_count` shows
    values > 0 for `interruption_reason="HW/SW Maintenance"`, it indicates the
    underlying Compute Engine VM was interrupted due to scheduled host
    maintenance.

### Step 3: [Low Risk] Investigation via Cloud Logging & Node Taints

-   **Action**: Call `query_logs` or instruct the user to filter their GKE logs
    for active host maintenance events, and check node taints.
-   **Guidance**: Look for occurrences in Cloud Logging where
    `cloud.google.com/active-node-maintenance` is set to `ONGOING`. To check if
    GKE has cordoned the terminating node to prevent new workloads from being
    scheduled, verify whether the
    `cloud.google.com/impending-node-termination:NoSchedule` taint is present
    (either in GKE event logs or directly via `kubectl describe node`).
-   **Interpretation**:
    -   `cloud.google.com/active-node-maintenance` set to `ONGOING` means
        workloads are actively being stopped by GKE due to host maintenance.
    -   `cloud.google.com/impending-node-termination:NoSchedule` taint means GKE
        has cordoned the node to prevent new Pods from being scheduled on the
        terminating node. DO NOT recommend tolerating this taint.

### Step 4: Conclusion and Resolution

-   **Action**: Provide a summary of findings to the user and suggest
    appropriate mitigation strategies if host maintenance events were confirmed
    or scheduled.
-   **Reporting Rule**: Signal Only. Report high-signal information indicating
    that the disruption was caused by Compute Engine host maintenance,
    specifically affecting the underlying GPU/TPU nodes. DO NOT dump raw logs.
-   **Negative Findings Rule-Out**: If node scheduled-maintenance labels, PromQL
    interruption counts, and active maintenance logs all return negative/empty
    results, definitively conclude that Compute Engine host maintenance did NOT
    cause the disruption. Direct the user to investigate application-level
    causes (such as OOMKill events, CUDA runtime errors, or resource limits) and
    do not propose host maintenance mitigations as the primary resolution.
-   **Mandatory Workload Protection Triad**: Whenever host maintenance is
    identified or anticipated on GPU/TPU nodes, consistently recommend all three
    complementary mitigations together:
    1.  **Configure Graceful Termination**: For workloads that need time to save
        state (e.g., ML frameworks checkpointing via Orbax), follow the guide to
        [Enable disruption handling](https://docs.cloud.google.com/kubernetes-engine/docs/concepts/handle-disruption-gpu-tpu#enabling-handling)
        and set `spec.terminationGracePeriodSeconds` (up to 60 minutes) to
        handle the `SIGTERM` signal before node shutdown.
    2.  **Enable Opportunistic Maintenance**: To automatically trigger
        maintenance when GKE detects that GPU/TPU nodes are idle, configure
        [Opportunistic Maintenance](https://docs.cloud.google.com/kubernetes-engine/docs/concepts/handle-disruption-gpu-tpu#opportunistic-maintenance).
    3.  **Configure PodDisruptionBudgets (PDBs)**: Ensure your workload uses a
        `PodDisruptionBudget` to maintain `minAvailable` replicas during
        evictions and disruptions.