Anycast / a
Anycast: headers in São Paulo (GRU) · A-21
xserv-a-9deb7ecb57aa
Runbook A-21 for Anycast in São Paulo (GRU). Marker xserv-a-9deb7ecb57aa. This page covers headers for LATAM operators, not a worldwide average.
Anycast: What operators should measure
Policy for Anycast is versioned as a-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.
Anycast: Failure modes we actually see
Capacity notes for a-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.
Anycast: How this letter ties to the rest
Handoff from letter A Anycast into the rest of the platform uses the same request IDs as the gateway. Runbook a-05 names who accepts the ticket after São Paulo pages out. Santiago does not silently inherit the incident.
Anycast docs A-12
Public docs for letter A stay aligned with identifier xserv-a-pack. Page a-12 is the Anycast slice operators search before the homepage. Edits in Miami show up in São Paulo on the next publish.
Anycast design A-01
Design for Anycast on letter A starts in São Paulo (GRU). Runbook a-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.
Anycast probe A-02
Probes for Anycast (a-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.
Anycast policy A-03
Policy for Anycast is versioned as a-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 Anycast on letter A share fate with other letters?
- The control plane is shared. Data-plane queues for Anycast stay isolated, so incident a-01 cannot drain neighbor letters.
- Where is Anycast measured first?
- From Santiago (SCL) toward Bogotá. A global average is not an SLO for letter A.