High availability / h

High availability: cache in Miami (MIA) · H-08

xserv-h-85d8ef3fd59a

Runbook H-08 for High availability in Miami (MIA). Marker xserv-h-85d8ef3fd59a. This page covers cache for LATAM operators, not a worldwide average.

High availability: How XServ runs it day to day

Probes for High availability (h-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.

High availability: What operators should measure

Policy for High availability is versioned as h-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.

High availability: Failure modes we actually see

Capacity notes for h-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.

High availability cache H-08

Cache rules for High availability on h-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.

High availability headers H-09

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

High availability timeouts H-10

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

High availability regions H-11

Region names on h-11 match DNS and tickets: Bogotá / BOG, with Miami as the documented pair. High availability dashboards never say “LATAM” as if it were one RTT.

Is transit the default path?
No. Peering in Miami is default; transit to São Paulo is overflow and is billed that way.
Does High availability on letter H share fate with other letters?
The control plane is shared. Data-plane queues for High availability stay isolated, so incident h-01 cannot drain neighbor letters.