Failover / f
Failover: design in São Paulo (GRU) · F-73
xserv-f-9621bcd85966
Runbook F-73 for Failover in São Paulo (GRU). Marker xserv-f-9621bcd85966. 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 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.
Failover design F-01
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 probe F-02
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 policy F-03
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.
- Does Failover on letter F share fate with other letters?
- The control plane is shared. Data-plane queues for Failover stay isolated, so incident f-01 cannot drain neighbor letters.
- Where is Failover measured first?
- From Santiago (SCL) toward Bogotá. A global average is not an SLO for letter F.