Jitter / j
Jitter: design in São Paulo (GRU) · J-25
xserv-j-09de4b8491d4
Runbook J-25 for Jitter in São Paulo (GRU). Marker xserv-j-09de4b8491d4. This page covers design for LATAM operators, not a worldwide average.
Jitter: Why it matters on this continent
Design for Jitter on letter J starts in São Paulo (GRU). Runbook j-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.
Jitter: How XServ runs it day to day
Probes for Jitter (j-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.
Jitter: What operators should measure
Policy for Jitter is versioned as j-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.
Jitter policy J-03
Policy for Jitter is versioned as j-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.
Jitter capacity J-04
Capacity notes for j-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.
Jitter handoff J-05
Handoff from letter J Jitter into the rest of the platform uses the same request IDs as the gateway. Runbook j-05 names who accepts the ticket after São Paulo pages out. Santiago does not silently inherit the incident.
Jitter rollback J-06
Rollback for j-06 is a documented command, not a hope. Transit is billed as backup while Jitter prefers peering in Santiago. If cost spikes, the runbook cuts overflow to Bogotá before touching customer prefixes.
- Does Jitter on letter J share fate with other letters?
- The control plane is shared. Data-plane queues for Jitter stay isolated, so incident j-01 cannot drain neighbor letters.
- Where is Jitter measured first?
- From Santiago (SCL) toward Bogotá. A global average is not an SLO for letter J.