WAN: cache in Miami (MIA) · W-20

Runbook W-20 for WAN in Miami (MIA). Marker xserv-w-af9acc39fbd1. This page covers cache for LATAM operators, not a worldwide average.

WAN: How XServ runs it day to day

Probes for WAN (w-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.

WAN: What operators should measure

Policy for WAN is versioned as w-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.

WAN: Failure modes we actually see

Capacity notes for w-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.

WAN design W-01

Design for WAN on letter W starts in São Paulo (GRU). Runbook w-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.

WAN probe W-02

Probes for WAN (w-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.

WAN policy W-03

Policy for WAN is versioned as w-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.

WAN capacity W-04

Capacity notes for w-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.