Gke AI Troubleshooting Tpu Vbar Oom
GoogleOfficialPublished by Google
- Skill
- Review and audit
- Cloud and DevOps
- Apache-2.0
- Low risk
- Has scripts
AutoGineer summary
Written by AutoGineer from the skill’s own files, not by the author
This skill provides a systematic diagnostic and resolution workflow for troubleshooting vbar_control_agent segfaults and OOM errors on GKE TPU v6e nodes. These issues are often caused by race conditions during TPU device resets or high-frequency metrics polling. The skill guides users through log analysis using Cloud Logging to identify memory cgroup OOMs and metrics fetch failures, and provides steps to mitigate these issues by identifying and disabling conflicting custom metrics collection.
What it does
- Analyzes serial console logs for vbar_control_agent OOM and segfault signatures.
- Investigates tpu-device-plugin metrics fetch failures indicating vBAR memory corruption.
- Identifies potential conflicts from custom TPU metrics collection scripts or agents.
- Provides a structured workflow to isolate the root cause of TPU device initialization failures.
- Offers actionable resolution steps including disabling conflicting metrics collectors.
- Advises on long-term mitigation through GKE version upgrades.
When to use it
- When troubleshooting vbar_control_agent crashes on GKE TPU v6e nodes.
- When memory cgroup OOM errors appear in serial console logs.
- When tpu-device-plugin reports metrics checksum corruption errors.
- When investigating TPU device initialization failures or custom metrics collection conflicts.
Advantages
- Reduces mean time to resolution for complex TPU-related node failures.
- Provides specific log filter templates for targeted diagnostics.
- Helps distinguish between transient race conditions and persistent configuration issues.
- Includes clear guidance on attribution for GCP command execution.
Usage examples
- “My TPU v6e node is crashing, how do I check for vbar_control_agent OOMs?”
- The agent will guide you through calculating the time window and applying the specific Cloud Logging filter to search serial console logs for vbar_control_agent OOM signatures.
- “How do I investigate tpu-device-plugin metrics fetch failures?”
- The agent will provide a log query to search for checksum mismatch errors in the tpu-device-plugin container logs to confirm vBAR memory corruption.
Install
Download the skill as a ZIP:
https://autogineer.com/agent-skills/google/gke-ai-troubleshooting-tpu-vbar-oom/downloadUnzip it into the cross-client skills folder of your project:
mkdir -p .agents/skills && unzip gke-ai-troubleshooting-tpu-vbar-oom.zip -d .agents/skills
Documentation by Google
TPU Connection Failure and VBAR OOM Troubleshooting
Use this skill to systematically diagnose and prevent vbar_control_agent
segfaults and Out-Of-Memory (OOM) errors on TPU v6e nodes.
Attribution
MUST READ: Before executing any gcloud, REST API, or MCP command, you
MUST read Usage Attribution. 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-tpu-vbar-oom)"
and append agent-skills/1.0 (skill:gke-ai-troubleshooting-tpu-vbar-oom) to User-Agent headers.
⚠️ Prerequisites
Cloud Logging must be enabled for the project.
Access to the project and cluster via
gcloudor equivalent tool.
🔍 Diagnostic Workflow
Step 0: Context Acquisition & Time Window Definition
Independently gather required context using available GCP/GKE tools or use the
provided {variable} placeholders:
{project_id}: The GCP Project ID (e.g.,customer-ai-project-123).{cluster_name}: The GKE Cluster Name (e.g.,tpu-cluster-prod).{node_name}: The Node Name or Instance ID (e.g.,tpu-node-1).{workload_name}: The Workload Name / JobSet Name (e.g.,my-training-job-456).{namespace}: The Workload Namespace.{issue_time}: The timestamp of the issue (e.g.,2026-04-14T20:00:00Z).
Time Handling & Execution Rules
Window Calculation: If an issue timestamp
{issue_time}is provided, calculate the query time window as[{issue_time} - 30m]to[{issue_time} + 30m].Let
{start_time}={issue_time} - 30mLet
{end_time}={issue_time} + 30m
Informational vs. Live Execution: If the user request is informational or query-formulation (e.g. "How can I check...", "How do I determine..."), or if live GCP project resources are not actively targetable, directly output the calculated time window, log names, and Cloud Logging filter templates without attempting live log execution commands.
Step 1: Check for vbar_control_agent OOMs
Look for specific out of memory messages from vbar_control_agent in serial
console logs (serialconsole.googleapis.com%2fserial_port_1_output).
Tool to use:
query_logs(for live diagnostics)Filter Templates:
Serial Console Logs (OOMs):
logName="projects/{project_id}/logs/serialconsole.googleapis.com%2fserial_port_1_output"
AND labels."compute.googleapis.com/resource_name"="{node_name}"
AND SEARCH(text_payload, "Memory cgroup out of memory: Killed process .* (vbar_control_ag)")
AND timestamp >= "{start_time}"
AND timestamp <= "{end_time}"Logic: Presence of
Memory cgroup out of memorymessages related tovbar_control_agent. Stack traces pointing tolibtpu::tpunetd::VBARControlHelper::MetricsReadFromVBARare a strong indicator.Automation: Proceed to next step automatically after reporting findings.
Reference: See
references/failure_signatures.mdfor example log patterns.
Step 2: Investigate tpu-device-plugin Metrics Fetch Failures [Low Risk]
Check if tpu-device-plugin is reporting metric fetch failures.
Tool to use:
query_logsFilter Template:
resource.type="k8s_container"
AND resource.labels.project_id="{project_id}"
AND resource.labels.cluster_name="{cluster_name}"
AND resource.labels.container_name="tpu-device-plugin"
AND severity=ERROR
AND textPayload:"metrics fetch failed for .* deviceID and .* device path with error: checksum didn't match with the metrics data. Corrupt data found"
AND timestamp >= "{start_time}"
AND timestamp <= "{end_time}"Logic: Errors indicating "metrics fetch failed" with "checksum didn't match" suggest vBAR memory corruption.
Automation: Proceed to next step automatically after reporting findings.
Step 3: Check for Custom Metrics Collection Usage [Low Risk]
Inspect cluster configurations, workloads, or container specs to determine if custom TPU metrics collection mechanisms are deployed.
Action: Check if custom scripts or agents (e.g., using
libtpu.sdk.tpumonitoring) are deployed that frequently queryGetHostMetricsfromvBAR Control Agent.Verification Commands:
Kubectl Search (Inspect workload env/specs):
kubectl get pods -A -o jsonpath='{range .items[*]}{.metadata.namespace}{"/"}{.metadata.name}{"\t"}{.spec.containers[*].image}{"\n"}{end}'Log Search Filter (
query_logs):
resource.type="k8s_container" AND resource.labels.project_id="{project_id}" AND resource.labels.cluster_name="{cluster_name}" AND textPayload:"libtpu.sdk.tpumonitoring" AND timestamp >= "{start_time}" AND timestamp <= "{end_time}"Logic: Confirmation of custom metrics collection helps confirm the race condition hypothesis.
🛠️ Resolution Workflow
Resolution 1: Temporarily Disable Custom Metrics Collection [High Risk]
If a custom metrics collection agent is identified, recommend disabling it.
Action: Recommend disabling the custom metrics collector.
Justification: Prevents reads from vBAR during device resets, stopping crashes and OOMs.
Resolution 2: Await vbar_control_agent Resiliency Update [Low Risk]
Advise that a permanent fix will be available in a future GKE version.
Action: Recommend upgrading GKE when the fix is available.
Justification: The updated agent will be resilient to memory corruption and gracefully handle reads from unbound vBARs.
📋 copypaste checklist
[ ] Acquire context and compute
[{start_time}, {end_time}]window.[ ] Check for
vbar_control_agentsegfaults and OOMs usingquery_logs.[ ] Investigate
tpu-device-pluginfailures usingquery_logs.[ ] Inspect for custom metrics collection usage.
[ ] Advise disabling custom metrics collection if applicable.
[ ] Advise awaiting resiliency update.
Files
- ATTRIBUTION.mdAdded by AutoGineer888 B
- LICENSELicence file added by AutoGineer11.1 KiB
- SKILL.md6.7 KiB
- references/attribution.md1.9 KiB
- references/failure_signatures.md1.4 KiB
- scripts/validate_queries.shScript993 B
LICENSE
Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.
"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
"Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.
2. Grant of Copyright License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.
3. Grant of Patent License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
(b) You must cause any modified files to carry prominent notices
stating that You changed the files; and
(c) You must retain, in the Source form of any Derivative Works
that You distribute, all copyright, patent, trademark, and
attribution notices from the Source form of the Work,
excluding those notices that do not pertain to any part of
the Derivative Works; and
(d) If the Work includes a "NOTICE" text file as part of its
distribution, then any Derivative Works that You distribute must
include a readable copy of the attribution notices contained
within such NOTICE file, excluding those notices that do not
pertain to any part of the Derivative Works, in at least one
of the following places: within a NOTICE text file distributed
as part of the Derivative Works; within the Source form or
documentation, if provided along with the Derivative Works; or,
within a display generated by the Derivative Works, if and
wherever such third-party notices normally appear. The contents
of the NOTICE file are for informational purposes only and
do not modify the License. You may add Your own attribution
notices within Derivative Works that You distribute, alongside
or as an addendum to the NOTICE text from the Work, provided
that such additional attribution notices cannot be construed
as modifying the License.
You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "[]"
replaced with your own identifying information. (Don't include
the brackets!) The text should be enclosed in the appropriate
comment syntax for the file format. We also recommend that a
file or class name and description of purpose be included on the
same "printed page" as the copyright notice for easier
identification within third-party archives.
Copyright [yyyy] [name of copyright owner]
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Requirements and compatibility
Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta
“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.
Needs: Needs a command-line tool, Needs Node.js
Security
What our scanner noticed· Low risk
- Scripts that your agent may run
This skill includes scripts that your agent may run. Read them before you use it.
A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.
Attribution and licence
- Published by
- Publisher
- Google (Official)
- Source
- google/skills · skills/cloud/gke-ai-troubleshooting-tpu-vbar-oom · commit 2194d3b
- Licence
- Apache License 2.0 (redistribution allowed)
- LICENSE (added by AutoGineer from LICENSE)
- ATTRIBUTION.md (written by AutoGineer)
- Synced
AutoGineer is not affiliated with or endorsed by Google or Google.
Download ZIP
The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download gke-ai-troubleshooting-tpu-vbar-oom.zip