16 · Measure, protect, and pay for the service

Deep systems understanding · Study map 76 of 85

Observability: connect the user symptom to the machine

Suggested preparation: RL post-training: alternate generating and learning

Picture it

Imagine trying to diagnose a sick patient by only looking at their average heart rate over a year. A useful dashboard lets you zoom into the exact moment a symptom occurs and trace it to a specific blocked artery or misfiring nerve. A single aggregate number can easily mask a severe issue affecting just one crucial demographic or feature.

What to understand

  • Request traces, phase histograms, SLO/error budgets, and burn rates
  • Queue length, active tokens, preemption, cache hits, GPU/network health

Follow the references

  1. 1 · Documentation

    vLLM · Production metrics ↗

    Choose stage metrics and histogram buckets that support your SLOs.

  2. 2 · Documentation

    NVIDIA · DCGM feature overview ↗

    Add hardware counters only when they help distinguish a suspected bottleneck.

Make it concrete

Create a dashboard specification with a user-facing symptom, a diagnostic metric, and an action for each alert. Avoid logging raw prompts by default.

You understand it when…

TTFT rises while GPU activity falls. What correlated signals would separate a tokenizer bottleneck from slow weight loading?

This is a study map. Follow the reference for the full explanation; use the question to test your mental model. Browse the reference shelf.