Introducing TorchPass Snapshots: Protect training progress. Free up GPU capacity. No training-code changes.

Launching YOCO (You Only Compute Once): Industry’s First Contractual Guarantee To End GPU Waste In AI Training

Replay the Webinar: Navigating Networking Transitions Shaping AI Infra Economics: Scaling Up, Out, and Across

Play SemiAnalysis-Clockwork Webinar: Comparing Fault Tolerance Frameworks & TCO Impact

AI Fabric Observability

Where exactly is my fabric problem?

A job slows down or fails. Is the network to blame? And if so, where exactly? Clockwork FleetLens definitively rules whether the fabric is at fault and, when it is, pinpoints the exact link, switch or NIC, so you stop guessing and stop burning GPU-hours on blind spots.

Gray failures, found
Workload-impacting fabric degradation that existing tools miss
The exact link, named
Not a guess or a subnet: the link, switch or NIC at fault, with evidence
100% software
No hardware taps, no fabric changes: runs on the hosts you already have
The problem today

Today’s AI observability tools leave you running blind.

“Is the network to blame? And if so, where exactly is the problem?”

The fabric is complex, and the hardest part of the stack to diagnose

Today’s large AI factories have hundreds of switches and tens of thousands of links and transceivers, any one of which can quietly degrade. Troubleshooting at this scale is like finding a needle in a haystack.

Blackwell Ultra · Quantum-X800 InfiniBand

DGX GB300 SuperPOD

9,216
GPUs
800 Gbps
Link speed
128
Leaf switches
72
Spine switches
~18,000
Network links
~23,000
Transceivers
Collectives run at the speed of the slowest link
The smallest network degradation slows down the entire collective.
Today’s tools leave you blind
10–60 s sampling misses µs-scale events, inability to measure exact one-way delay.
Every blind spot burns GPU-hours
While teams argue over whose problem it is, thousands of GPUs sit idle.
FleetLens

Clockwork has built the foundational blocks needed to uncover fabric blind spots.

FleetLens is built on four foundational technologies that see every link in the fabric, every 10 milliseconds, and pinpoint exactly where it is degrading. This is supplemented by telemetry from the host, fabric and workload.

Sub-µs clock synchronization makes timestamps directly comparable across the fabric.
Measures exact one-way delays between NIC pairs every 10ms.
Adds rail, leaf, spine, port and link context to each probe.
Finds the narrowest shared element that explains the problem.
Sensors
Host
Fabric
Workload
Out-of-Band Probemesh

Probemesh: thousands of tiny probes measure every path in the fabric, every 10 milliseconds.

Probemesh sends lightweight out-of-band probes between NIC pairs across the fabric every 10 milliseconds. Because every clock is synchronized to sub-µs accuracy, the probes can measure the exact one-way delays in each direction. The result is a live, high-resolution directional map of the whole fabric.

Probes are sent across link pairs every 10 milliseconds.
FleetLens · Fabric detections

FleetLens detects the problem, and definitively rules whether the fabric is at fault.

FleetLens detects slow or failing jobs and definitively rules whether the fabric is to blame. When it is, FleetLens pinpoints the exact link, switch or NIC at fault. It surfaces the hidden, workload-impacting issues other tools miss: congestion and micro-congestion, topology-specific degradation, gray failures and unexplained slowdowns.

Is there a problem?
Telemetry is continuously evaluated against a corpus of detections.
Who is affected?
Correlation shows affected jobs, tenants and components.
Where to start looking?
Contextual evidence pinpoints where the problem lies and what to investigate.

The issues FleetLens finds but other tools miss

Congestion and micro-congestion

Oversubscribed paths, queue buildup, head-of-line blocking

Topology-aware degradation

Path asymmetry and cabling inconsistencies

Gray failures

Silently degraded switches and fabric components

Workload-visible slowdowns

Partial fabric, path or NIC problems with no obvious root cause

Misconfigurations

GDR, PCIe topology, firmware and driver mismatches

Detections with evidence and visualizations

Every detection comes with contextual drilldown to supporting evidence shown in Grafana dashboards.

All available as Prometheus metrics

Telemetry is available for scraping through a Prometheus endpoint.

FleetAudit · Pre-flight checks

FleetAudit: a known-good baseline before you commit GPU time.

Teams lose hours to faults that only surface once training or inference is already running: a degraded PCIe riser, a firmware mismatch, a misconfigured NCCL setting. Every one of them could have been caught before the job started. FleetAudit is the pre-flight check for your cluster.

40+
Automated checks per audit
Zero
Surprises when production starts
FleetAudit results: 7 issues found, 3 require action before running jobs; each finding lists impact, cause, action and affected components

Why FleetAudit matters

Confident cluster handoff.
Checks span frontend and backend, NCCL, NVSwitch, GPU health and PCIe topology.
Root cause isolation.
Unified drill-down correlates failures across configuration, GPU and network layers.
Interoperability through API.
Trigger audits from CI/CD, pull results and integrate into existing tools.

Integrates Seamlessly With Your Observability Stack

Expose fleet telemetry through open APIs and familiar dashboards.

Clockwork streams cross-stack metrics via a Prometheus-compatible API, integrating directly with Grafana and existing observability tools. Operators can unify fabric, workload, and system telemetry in a single pane of glass—eliminating silos, accelerating troubleshooting, and making AI infrastructure easier to operate at scale.

Clockwork API For Cross-stack Metrics Prometheus Compatible Databases 

Single Pane of Glass Grafana Dashboards

Single Pane of Glass Grafana Dashboards
Explainer videos

See it in four minutes

LinkPass
A link flaps mid-training and the job keeps running. See LinkPass reroute traffic in milliseconds.
TorchPass
Migrate a live job to spare GPUs and resume from the exact iteration, with no model code changes.
FleetAudit
Catch bad links, NICs and GPUs before a job starts, so every cluster is production-ready.

“Is it the network, compute, or our code?” Stop guessing.