Latency: design in São Paulo (GRU) · L-37

Runbook L-37 for Latency in São Paulo (GRU). Marker xserv-l-ad37fa49f266. This page covers design for LATAM operators, not a worldwide average.

Latency: Why it matters on this continent

Design for Latency on letter L starts in São Paulo (GRU). Runbook l-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.

Latency: How XServ runs it day to day

Probes for Latency (l-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.

Latency: What operators should measure

Policy for Latency is versioned as l-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.

Latency capacity L-04

Capacity notes for l-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.

Latency handoff L-05

Handoff from letter L Latency into the rest of the platform uses the same request IDs as the gateway. Runbook l-05 names who accepts the ticket after São Paulo pages out. Santiago does not silently inherit the incident.

Latency rollback L-06

Rollback for l-06 is a documented command, not a hope. Transit is billed as backup while Latency prefers peering in Santiago. If cost spikes, the runbook cuts overflow to Bogotá before touching customer prefixes.

Latency peering L-07

Peering for Latency (l-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.