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World O1: The Control Room

The four golden signals

You will learn: the four screens every control room hangs first, and which one warns earliest.

Checked with Prometheus 3 on 1 Nov 2026

The problem

Kedai Kancil has 500 numbers. The control room wall fits four screens. Which four?

Watch

Tap each point on the timeline.

Google’s SRE book calls them the four four golden signals: Latency, traffic, errors and saturation: the four screens to hang first.. Tap each one.

Try it

Find the saturation: How full the system is: a growing queue, a busy stove, a nearly full disk. screen: how full is the shop?

Tap the chip that shows how full the shop is, then press Run.

Metrics in this data (tap to add):

Time 0 is when the data starts. The query looks back from the eval time.

Predict

Run each chip and look at the graphs. Which signal went bad first?

Try it

Which signal is it? Sort each number.

Drag a card into a box. Or tap the card, then tap the box.

          Check

          Errors are 0%. But latency: How long one request takes, from asking to answer. is 9 seconds for every checkout. Is the shop healthy?

          You did it!

          You can now name the four golden signals and spot each one.

          Go deeper (optional)

          A tip from the SRE book: time failed requests apart from good ones. A fast error is not a good answer. A slow error is even worse.

          Real mission

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