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For aleph alpha infrastructure and model engineering teams

Aleph Alpha Scaling: find the error before a training collective stalls.

Review the parallelism configuration and earliest rank exception together. Distinguish setup and memory evidence from a later collective timeout.

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Replay a resolved Aleph Alpha workflow incident

Upload your log file. Review the selected evidence and masking, then run diagnosis. Keep the original log for any follow-up questions.

Before uploading, review cloud data handling and local options.

training_logs.txt
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Upload your log file. Large files are processed in your browser. Only selected evidence is submitted when you run diagnosis.

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Start your free 30-day Team evaluation

Up to 50 diagnoses a day for 30 days. Verify your work email to activate an eligible company evaluation, then replay a resolved incident and compare the evidence and next steps with your team's confirmed cause.

Use your company email (e.g. alex@yourcompany.com). Eligible company domains can activate a free 30-day Team evaluation (up to 50 diagnoses/day) after email and domain checks, regardless of mail host. Uncertain domains can request review from support@denpex.com. Free local diagnoses remain available without an account.

What a useful evaluation should establish

Compare the first failure, quoted evidence and unresolved questions with an incident your team has already resolved. Begin with this question: Which parallel training stage failed first? Only attribute a process, rank, device or recovery state when the submitted evidence establishes it.

Which parallel training stage failed first?

Evidence to compare: Per-rank logs, parallelism configuration and the first failing operation.

A pipeline peer can wait after another rank exits. Rank attribution requires identifiers in the submitted evidence, not an assumption based on the loudest timeout.

Did the environment fail before model execution?

Evidence to compare: Library revision, dependency versions and startup traceback.

The repository documents CUDA and extension dependencies. An import or extension failure must be separated from a live distributed communication fault.

Does the evidence support a memory or precision change?

Evidence to compare: The actual allocation or non-finite exception and relevant configuration.

A timeout alone does not justify changing precision or sharding. Compare the initiating error and a known good configuration before proposing a bounded next check.

Use Denpex alongside your existing telemetry tools to investigate submitted incident evidence. With monitoring configured on a supported plan, detected failures can trigger alerts and an automatic diagnosis from the captured evidence.

Inside Denpex

See the evidence, not just the claim

Follow the causal chain, inspect the quoted evidence and prepare the next handoff. These actual product captures use founder-account examples and the VS Code extension, with the source identified under each image. Open a capture to inspect it at full size.

Follow the failure through the cascade

Denpex founder-account example: a causal graph connects an Xid 48 ECC event to a rank exit and downstream collective failures, with quoted evidence for each stage.
Live founder-account capture from the bundled NCCL/ECC example. Follow the hardware event, rank exit and downstream symptoms with a supporting log quote at each stage.Inspect original image

Prepare the hardware escalation

Denpex hardware handoff summary asks the operator to capture diagnostic evidence and verify RMA eligibility with the vendor.
Actual hardware handoff summary from the same founder-account example. Capture diagnostic evidence before an approved reset, then confirm RMA eligibility with the vendor.Inspect original image

Ask for the evidence that is missing

Denpex historical example says a collective timeout does not establish the initiating rank, cause or failure domain and requests distinguishing evidence before a remedy.
Founder-account example restored from history. The original timeout remains unattributed, and the UI keeps the missing-evidence assessment visible.Inspect original image

Keep the investigation in the editor

Denpex VS Code extension displaying a bundled OOM-before-NCCL example, matched log evidence, verification guidance and an investigation handoff.
Actual VS Code extension capture of the bundled OOM-before-NCCL example. Review matched log evidence, verification guidance and the investigation handoff without leaving the editor.Inspect original image