Pages got fast again. Public marketing routes are still rendered
per-request by Next.js (force-dynamic, until the ISR bug gets isolated),
but their HTML is now cached at the Nginx layer for 60s with a 5-minute
stale-while-revalidate window. Result: only the first hit on a URL
inside a 60s window pays the SSR cost; every other visitor in that
window gets a sub-10ms cached response. While a cached entry is
revalidating, peers keep getting the stale copy — no cold starts, no
thundering herds.
NEXT.JS MIDDLEWARE (src/proxy.ts)
- isCacheablePublicPath() identifies routes safe to share-cache:
/, /<locale>, /<locale>/applications, /<locale>/news,
/<locale>/heritage. Excludes /<locale>/parts (auth-gated B2B portal)
and /hq-command/*, /api/*, /_next/*.
- hasAuthCookie() short-circuits caching when the request carries a
flux_session (admin CMS) or flux_b2b_session (client portal) cookie.
Authenticated users always get a fresh per-account render.
- When both checks pass, the response gets:
Cache-Control: public, s-maxage=60, stale-while-revalidate=300
NGINX (nginx/nginx.conf)
- New shared zone:
proxy_cache_path /var/cache/nginx/flux levels=1:2
keys_zone=flux_html:50m max_size=1g inactive=24h
use_temp_path=off;
- Access log gets a `cache=$upstream_cache_status` field so we can
audit hit/miss ratios in the live logs.
NGINX (nginx/conf.d/flux.conf — location /)
- proxy_cache flux_html + proxy_cache_revalidate on
- proxy_cache_use_stale: serves stale on backend errors / timeout /
during update, so 502s during a Next.js restart never reach users.
- proxy_cache_background_update + proxy_cache_lock: only one upstream
request fires when a cached entry expires; others keep getting stale.
- proxy_cache_bypass / proxy_no_cache wired to flux_session +
flux_b2b_session cookies — admin and B2B traffic skips the shared
cache entirely.
- X-Cache-Status response header (HIT/MISS/EXPIRED/STALE/UPDATING/BYPASS)
for live debugging — open dev tools, refresh, watch the value flip.
WHAT YOU'LL FEEL
- First visitor on /en within a 60s window: ~150-300ms (SSR + DB).
- Second through Nth visitors in the same window: <10ms.
- Editor publishes a change in HQ Command → revalidatePath() inside
the existing actions invalidates the Next.js cache; the next
marketing-page request rebuilds and primes Nginx fresh. The 60s
TTL bounds how long stale content can linger if revalidation is
ever skipped.
NO BREAKING CHANGES
- Auth flows untouched (cookies bypass cache).
- HQ Command + API endpoints untouched (separate Nginx locations).
- Static assets (cases/, applications/, /branding/, /_next/static)
unaffected — they had their own cache headers already.
- Server-side cache invalidation via revalidatePath() still works.
DEPLOY (David)
cd /opt/flux-srl
git pull
docker compose up -d --build app
docker compose exec nginx nginx -t
docker compose exec nginx nginx -s reload
davidherran