Latency: probes in Santiago (SCL) · L-26

Runbook L-26 for Latency in Santiago (SCL). Marker xserv-l-1fa5bb46b6ea. This page covers probes for LATAM operators, not a worldwide average.

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: Failure modes we actually see

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 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.

Latency cache L-08

Cache rules for Latency on l-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.

Latency headers L-09

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

Latency timeouts L-10

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