Sync / y
Sync: design in São Paulo (GRU) · Y-61
xserv-y-0a5a6523a814
Runbook Y-61 for Sync in São Paulo (GRU). Marker xserv-y-0a5a6523a814. This page covers design for LATAM operators, not a worldwide average.
Sync: Why it matters on this continent
Design for Sync on letter Y starts in São Paulo (GRU). Runbook y-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.
Sync: How XServ runs it day to day
Probes for Sync (y-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.
Sync: What operators should measure
Policy for Sync is versioned as y-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.
Sync policy Y-03
Policy for Sync is versioned as y-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.
Sync capacity Y-04
Capacity notes for y-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.
Sync handoff Y-05
Handoff from letter Y Sync into the rest of the platform uses the same request IDs as the gateway. Runbook y-05 names who accepts the ticket after São Paulo pages out. Santiago does not silently inherit the incident.
Sync rollback Y-06
Rollback for y-06 is a documented command, not a hope. Transit is billed as backup while Sync prefers peering in Santiago. If cost spikes, the runbook cuts overflow to Bogotá before touching customer prefixes.
- Does Sync on letter Y share fate with other letters?
- The control plane is shared. Data-plane queues for Sync stay isolated, so incident y-01 cannot drain neighbor letters.
- Where is Sync measured first?
- From Santiago (SCL) toward Bogotá. A global average is not an SLO for letter Y.