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.

Where is High availability measured first?

From Santiago (SCL) toward Bogotá. A global average is not an SLO for letter H.

High availability: headers in São Paulo (GRU) · H-33

Runbook H-33 for High availability in São Paulo (GRU). Marker xserv-h-d6479bd7ccce. This page covers headers for LATAM operators, not a worldwide average.

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: How this letter ties to the rest

Handoff from letter H High availability into the rest of the platform uses the same request IDs as the gateway. Runbook h-05 names who accepts the ticket after São Paulo pages out. Santiago does not silently inherit the incident.

High availability peering H-07

Peering for High availability (h-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.

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.