Where is DNS measured first?

From Santiago (SCL) toward Bogotá. A global average is not an SLO for letter D.

How fast is rollback for d-03?

The runbook is a command plus a named owner. There is no wait for a weekly change freeze.

DNS: probes in Santiago (SCL) · D-62

Runbook D-62 for DNS in Santiago (SCL). Marker xserv-d-b7975978b00a. This page covers probes for LATAM operators, not a worldwide average.

DNS: How XServ runs it day to day

Probes for DNS (d-02) leave Santiago every 15s toward Bogotá. XServ pages the named owner if loss or RTT crosses the letter budget. A probe never shares a queue with bulk transfers, so a saturated WAN does not hide a dead PoP.

DNS: What operators should measure

Policy for DNS is versioned as d-03. Operators measure error rate, p95 from Bogotá, and time-to-rollback — not a worldwide average. Changes land in Bogotá first, then Miami, with a hold if either region regresses.

DNS: Failure modes we actually see

Capacity notes for d-04 assume rainy-season power in Miami and festival peaks toward São Paulo. The failure we actually see is a single uplink, not a cartoon partition of the whole continent. Spare ports and a second provider sit on the same runbook.

DNS cache D-08

Cache rules for DNS on d-08 keep language-correct objects near Miami. São Paulo is a sibling cache, not an origin. TTLs are short enough that a bad asset does not live through a weekend.

DNS headers D-09

Headers for d-09 carry the letter, the region (GRU) and a request id. DNS debugging in São Paulo should not require a packet capture in Santiago first.

DNS timeouts D-10

Timeouts on d-10 are tighter than the WAN RTT to Bogotá. DNS in Santiago fails fast and retries once; a third try needs a human because it is no longer a blip.

DNS regions D-11

Region names on d-11 match DNS and tickets: Bogotá / BOG, with Miami as the documented pair. DNS dashboards never say “LATAM” as if it were one RTT.