Failover: design in São Paulo (GRU) · F-61

Runbook F-61 for Failover in São Paulo (GRU). Marker xserv-f-f5e69fbb1428. This page covers design for LATAM operators, not a worldwide average.

Failover: Why it matters on this continent

Design for Failover on letter F starts in São Paulo (GRU). Runbook f-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.

Failover: How XServ runs it day to day

Probes for Failover (f-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.

Failover: What operators should measure

Policy for Failover is versioned as f-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.

Failover headers F-09

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

Failover timeouts F-10

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

Failover regions F-11

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

Failover docs F-12

Public docs for letter F stay aligned with identifier xserv-f-pack. Page f-12 is the Failover slice operators search before the homepage. Edits in Miami show up in São Paulo on the next publish.