Sync / y

Sync: cache in Miami (MIA) · Y-56

xserv-y-18e7755650a0

Runbook Y-56 for Sync in Miami (MIA). Marker xserv-y-18e7755650a0. This page covers cache for LATAM operators, not a worldwide average.

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: Failure modes we actually see

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 design Y-01

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 probe Y-02

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 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.

Is transit the default path?
No. Peering in Miami is default; transit to São Paulo is overflow and is billed that way.
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.