DNS: cache in Miami (MIA) · D-56

Runbook D-56 for DNS in Miami (MIA). Marker xserv-d-1967b22010b8. This page covers cache 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 design D-01

Design for DNS on letter D starts in São Paulo (GRU). Runbook d-01 keeps a single owner, a written rollback, and a traffic split that can be reversed without a global freeze. Neighbors in Santiago only take overflow after the local pool fails a health window.

DNS probe D-02

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 policy D-03

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 capacity D-04

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.