Glossary · Measurement and evidence
canary
A known input sent through a system on a schedule so that its arrival, not the absence of an error, proves the path works.
What canary means
A known input sent through a system on a schedule so that its arrival, not the absence of an error, proves the path works. A canary message to an alert address, confirmed by reading the mailbox, catches a suppressed or bounced destination that every send-side check reports as success.
What canary can and cannot support
| It can support | It cannot support |
|---|---|
| A canary message to an alert address, confirmed by reading the mailbox, catches a suppressed or bounced destination that every send-side check reports as success. | A known input sent through a system on a schedule so that its arrival, not the absence of an error, proves the path works. |
Where canary comes up on this site
- Five days of our alerts went to an address with no mailboxThe check that would have caught it A canary: one message per day to the operator address, from the same binding, carrying a token, and a receiver that reads the mailbox and confirms the token arrived.
Related terms in Measurement and evidence
The vocabulary for saying how strongly something is known.
evidence level · false positive · denominator note · percentile rank · population baseline · cohort asymmetry · self-audit invariant · unscored measurement · dated series · change receipt · regression · finding age · graded through a wall · self-audit · placeholder in record · fetcher disagreement · own-host loop · score version · row review · double-counted defect · cosmetic row · gated row · log file analysis · AI referral attribution · finding fingerprint · finding state · headroom · fix list · render gap · lab data · Lighthouse · RUM · LCP · CLS · INP · topicality · intent coverage · citation rate · presence rate · answer stability
Questions about canary
What is canary?
A known input sent through a system on a schedule so that its arrival, not the absence of an error, proves the path works.
What does canary not show or guarantee?
A known input sent through a system on a schedule so that its arrival, not the absence of an error, proves the path works.
Which area of the glossary does canary belong to?
Measurement and evidence: The vocabulary for saying how strongly something is known.
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See it in the full glossary · 668 terms across 19 areas.