Anycast: headers in São Paulo (GRU) · A-57

Runbook A-57 for Anycast in São Paulo (GRU). Marker xserv-a-dd9ee4f474b4. 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 peering A-07

Peering for Anycast (a-07) prefers the IX fabric that already carries last-mile ISPs in Bogotá. Session counts and prefix limits are on the same page as the Miami backup path.

Anycast cache A-08

Cache rules for Anycast on a-08 keep language-correct objects near Miami. São Paulo is a sibling cache, not an origin. TTLs are short enough that a bad asset does not live through a weekend.

Anycast headers A-09

Headers for a-09 carry the letter, the region (GRU) and a request id. Anycast debugging in São Paulo should not require a packet capture in Santiago first.

Anycast timeouts A-10

Timeouts on a-10 are tighter than the WAN RTT to Bogotá. Anycast in Santiago fails fast and retries once; a third try needs a human because it is no longer a blip.