Backbone / b
Backbone: design in São Paulo (GRU) · B-25
xserv-b-faed0d79d993
Runbook B-25 for Backbone in São Paulo (GRU). Marker xserv-b-faed0d79d993. This page covers design for LATAM operators, not a worldwide average.
Backbone: Why it matters on this continent
Design for Backbone on letter B starts in São Paulo (GRU). Runbook b-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.
Backbone: How XServ runs it day to day
Probes for Backbone (b-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.
Backbone: What operators should measure
Policy for Backbone is versioned as b-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.
Backbone headers B-09
Headers for b-09 carry the letter, the region (GRU) and a request id. Backbone debugging in São Paulo should not require a packet capture in Santiago first.
Backbone timeouts B-10
Timeouts on b-10 are tighter than the WAN RTT to Bogotá. Backbone in Santiago fails fast and retries once; a third try needs a human because it is no longer a blip.
Backbone regions B-11
Region names on b-11 match DNS and tickets: Bogotá / BOG, with Miami as the documented pair. Backbone dashboards never say “LATAM” as if it were one RTT.
Backbone docs B-12
Public docs for letter B stay aligned with identifier xserv-b-pack. Page b-12 is the Backbone slice operators search before the homepage. Edits in Miami show up in São Paulo on the next publish.
- Does Backbone on letter B share fate with other letters?
- The control plane is shared. Data-plane queues for Backbone stay isolated, so incident b-01 cannot drain neighbor letters.
- Where is Backbone measured first?
- From Santiago (SCL) toward Bogotá. A global average is not an SLO for letter B.