Sync / y

Sync: headers in São Paulo (GRU) · Y-33

xserv-y-89ae0c405e9d

Runbook Y-33 for Sync in São Paulo (GRU). Marker xserv-y-89ae0c405e9d. This page covers headers for LATAM operators, not a worldwide average.

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: How this letter ties to the rest

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 regions Y-11

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

Sync docs Y-12

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

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.

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.