Files
orca/cloud/dev/scripts/relay-load-model.mjs
Jinwoo-H 25e31c931d chore(cloud): add the relay fence broker, ops console, Terraform root, and scripts
Copies the private repository's relay side: the IAM-only fence broker, the
operations console and incident monitor, the relay Terraform root with its
backend configuration and tfvars, and the deploy/capacity/admission/rehome/
monitoring scripts the workflows call, with their contract tests, contracts,
and fixtures.

The foundation and apps Terraform roots and the API and auth services stay
private. Four surfaces that spanned both trees are narrowed to the relay side
rather than left with a dangling read: the infra runner and the root-partition
and workload-identity-condition renderers now declare only the relay root, and
the Cloud SQL rollout census drops the six app workflows that are not here.
2026-09-03 06:20:32 -04:00

77 lines
3.1 KiB
JavaScript

const HEARTBEAT_INTERVAL_MS = 15_000
const REFRESH_MIN_MS = 180_000
const REFRESH_MAX_MS = 240_000
function mix32(value) {
let mixed = value >>> 0
mixed = Math.imul(mixed ^ (mixed >>> 16), 0x21f0aaad)
mixed = Math.imul(mixed ^ (mixed >>> 15), 0x735a2d97)
return (mixed ^ (mixed >>> 15)) >>> 0
}
function fraction(seed, index, stream) {
return mix32(seed ^ Math.imul(index + 1, 0x9e3779b1) ^ stream) / 0x1_0000_0000
}
export function controlPhase(controlIndex, seed = 0x4f524341) {
const refreshIntervalMs = Math.round(
REFRESH_MIN_MS + fraction(seed, controlIndex, 2) * (REFRESH_MAX_MS - REFRESH_MIN_MS)
)
return {
heartbeatOffsetMs: Math.floor(fraction(seed, controlIndex, 1) * HEARTBEAT_INTERVAL_MS),
refreshIntervalMs,
refreshOffsetMs: Math.floor(fraction(seed, controlIndex, 3) * refreshIntervalMs),
reconnectJitterMs: Math.floor(fraction(seed, controlIndex, 4) * 30_000)
}
}
export function modeledRelayLoad(controlCount, durationMs = 15 * 60_000, seed) {
if (!Number.isInteger(controlCount) || controlCount < 1) throw new Error('controlCount must be positive')
const bins = Array.from({ length: Math.ceil(durationMs / 1000) }, () => ({ pings: 0, refreshes: 0 }))
for (let controlIndex = 0; controlIndex < controlCount; controlIndex++) {
const phase = controlPhase(controlIndex, seed)
for (let at = phase.heartbeatOffsetMs; at < durationMs; at += HEARTBEAT_INTERVAL_MS) {
bins[Math.floor(at / 1000)].pings++
}
for (let at = phase.refreshOffsetMs; at < durationMs; at += phase.refreshIntervalMs) {
bins[Math.floor(at / 1000)].refreshes++
}
}
const totals = bins.reduce(
(result, bin) => ({
pings: result.pings + bin.pings,
refreshes: result.refreshes + bin.refreshes
}),
{ pings: 0, refreshes: 0 }
)
const durationSeconds = durationMs / 1000
return {
controlCount,
durationMs,
expectedPingRate: controlCount / (HEARTBEAT_INTERVAL_MS / 1000),
expectedRefreshRate: controlCount / ((REFRESH_MIN_MS + REFRESH_MAX_MS) / 2 / 1000),
observedPingRate: totals.pings / durationSeconds,
observedRefreshRate: totals.refreshes / durationSeconds,
maxPingBurst: Math.max(...bins.map(({ pings }) => pings)),
maxRefreshBurst: Math.max(...bins.map(({ refreshes }) => refreshes))
}
}
export function assertSpreadModel(model) {
const pingTolerance = model.expectedPingRate * 0.03 + 1
const refreshTolerance = model.expectedRefreshRate * 0.08 + 1
if (Math.abs(model.observedPingRate - model.expectedPingRate) > pingTolerance) {
throw new Error('modeled heartbeat rate diverged from the 15-second contract')
}
if (Math.abs(model.observedRefreshRate - model.expectedRefreshRate) > refreshTolerance) {
throw new Error('modeled token refresh rate diverged from the 180-240 second contract')
}
if (model.maxPingBurst > model.expectedPingRate * 1.3 + 5) {
throw new Error('heartbeat phase spreading produced a reconnect cliff')
}
// One-second bins have Poisson-sized tails even with uniform phase spreading.
if (model.maxRefreshBurst > model.expectedRefreshRate * 1.75 + 5) {
throw new Error('refresh phase spreading produced an auth herd')
}
}