DNS / d
DNS: cache in Miami (MIA) · D-32
xserv-d-3c7a7ceee78d
Runbook D-32 for DNS in Miami (MIA). Marker xserv-d-3c7a7ceee78d. This page covers cache for LATAM operators, not a worldwide average.
DNS: How XServ runs it day to day
Probes for DNS (d-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.
DNS: What operators should measure
Policy for DNS is versioned as d-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.
DNS: Failure modes we actually see
Capacity notes for d-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.
DNS policy D-03
Policy for DNS is versioned as d-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.
DNS capacity D-04
Capacity notes for d-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.
DNS handoff D-05
Handoff from letter D DNS into the rest of the platform uses the same request IDs as the gateway. Runbook d-05 names who accepts the ticket after São Paulo pages out. Santiago does not silently inherit the incident.
DNS rollback D-06
Rollback for d-06 is a documented command, not a hope. Transit is billed as backup while DNS prefers peering in Santiago. If cost spikes, the runbook cuts overflow to Bogotá before touching customer prefixes.
- Is transit the default path?
- No. Peering in Miami is default; transit to São Paulo is overflow and is billed that way.
- Does DNS on letter D share fate with other letters?
- The control plane is shared. Data-plane queues for DNS stay isolated, so incident d-01 cannot drain neighbor letters.