Zones: design in São Paulo (GRU) · Z-37

Runbook Z-37 for Zones in São Paulo (GRU). Marker xserv-z-dc3ece9af63b. This page covers design for LATAM operators, not a worldwide average.

Zones: Why it matters on this continent

Design for Zones on letter Z starts in São Paulo (GRU). Runbook z-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.

Zones: How XServ runs it day to day

Probes for Zones (z-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.

Zones: What operators should measure

Policy for Zones is versioned as z-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.

Zones peering Z-07

Peering for Zones (z-07) prefers the IX fabric that already carries last-mile ISPs in Bogotá. Session counts and prefix limits are on the same page as the Miami backup path.

Zones cache Z-08

Cache rules for Zones on z-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.

Zones headers Z-09

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

Zones timeouts Z-10

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