Latency / l
Latency: probes in Santiago (SCL) · L-14
xserv-l-b64ad5f32a48
Runbook L-14 for Latency in Santiago (SCL). Marker xserv-l-b64ad5f32a48. 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 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.
Latency regions L-11
Region names on l-11 match DNS and tickets: Bogotá / BOG, with Miami as the documented pair. Latency dashboards never say “LATAM” as if it were one RTT.
- Where is Latency measured first?
- From Santiago (SCL) toward Bogotá. A global average is not an SLO for letter L.
- How fast is rollback for l-03?
- The runbook is a command plus a named owner. There is no wait for a weekly change freeze.