¶Askr power features (0.3.0)

Seven capabilities that fall out of Askr's architecture — the shared-memory substrate, the CoW template, and owning the whole request lifecycle in-process.

¶1. Response cache with instant tag invalidation

A full-response edge cache in the binary. PHP marks a response cacheable; a later matching anonymous GET/HEAD is served straight from Rust, never touching PHP — static-file speed for cacheable pages, no Varnish, no Redis.

Enable:

askr serve … --response-cache 512        # ~140 KB per slot
# askr.toml → [cache] response_slots = 512

Opt a response in (the app decides what's safe to cache):

// cache for 60s, tagged so it can be invalidated later
header('Askr-Cache: 60, tags=posts,homepage');

Invalidate everything with a tag — instantly, across all workers (O(1)):

askr_cache_forget_tag('posts');   // e.g. in a Post::saved() observer

• Only cookie-less GET/HEAD are cacheable; Set-Cookie is stripped on store so a cached page can't pin one session onto every visitor.
• Responses carry X-Askr-Cache: HIT|MISS; hit-rate shows on the dashboard.
• askr_cache_flush() clears the response cache too.

¶2. Request coalescing (singleflight)

When identical cacheable requests hit a cold cache at the same time, one runs PHP (the leader) and the rest wait for it to populate the cache, then are served from it. Cache stampedes are eliminated across worker processes — automatic whenever the response cache is enabled.

¶3. Pusher-compatible WebSocket (drop-in Reverb)

Real-time without Reverb or an external broker. Laravel Echo talks to Askr with no frontend config change.

askr serve … --pusher          # auto-enables the broadcast ring
# askr.toml → [pusher] enabled = true

• WS endpoint ws://…/app/{key} — pusher:connection_established, subscribe / unsubscribe, ping/pong.
• HTTP trigger POST /apps/{id}/events — the Pusher API Laravel's broadcaster calls server-side; publishes into the shared broadcast ring so a trigger in any worker reaches subscribers in all of them.
• askr_broadcast('channel', $json) from PHP also reaches Pusher clients.

Private & presence channels are verified against the app secret (0.3.1):

askr serve … --pusher --pusher-secret "$PUSHER_APP_SECRET"
# or $ASKR_PUSHER_SECRET / [pusher] secret in askr.toml

A private-/presence- subscription must carry a valid auth token — the same HMAC-SHA256(secret, "socket_id:channel[:channel_data]") Laravel's /broadcasting/auth produces — or it's rejected with a subscription_error. Point Laravel's pusher driver at Askr (matching key/secret) and Echo just works:

// config/broadcasting.php → connections.pusher
'key'    => env('PUSHER_APP_KEY'),
'secret' => env('PUSHER_APP_SECRET'),   // must match --pusher-secret
'options' => [
    'host'   => env('PUSHER_HOST', '127.0.0.1'),
    'port'   => env('PUSHER_PORT', 443),
    'scheme' => env('PUSHER_SCHEME', 'https'),
],

Without a secret configured, private/presence subscriptions are accepted (dev).

¶4. askr_defer() — work after the response is sent

askr_defer(function () use ($user) {
    Mail::to($user)->send(new Welcome());   // runs after the client has the reply
});

Rust flushes the response, then the worker runs deferred closures before taking the next request. Octane-style deferred work with no queue infrastructure. Each callback is isolated — a thrown exception can't poison the next one.

¶5. Elastic worker autoscaling (CoW)

Process autoscaling has never been practical for PHP (~300 ms cold boot). The CoW template's ~ms warm respawn makes it cheap:

askr serve … --cow --worker-script … --workers-min 2 --workers-max 12
# askr.toml → [server] workers_min = 2 / workers_max = 12

The template reads a live queue-depth signal from shared memory, forks warm workers when requests queue, and harvests them back to the floor when idle.

¶6. Record & replay of failing requests

askr serve … --record-errors /var/lib/askr/errors    # persist every 5xx
askr replay /var/lib/askr/errors/<id>.json           # reproduce it exactly

A 5xx writes its full CGI envelope (method, URI, $_SERVER, raw body). askr replay reconstructs the exact request against a fresh interpreter and prints the status, headers and body — production debugging goes from "try to reproduce" to "replay it". Recent failures are listed on the admin dashboard.

Captures request bodies — treat the directory as sensitive.

¶7. Fork-based parallel test runner

askr test --root /path/to/app --runner examples/askr-test.php tests/

Boots the interpreter once (opcache warm and shared), then forks a fresh process per test file: perfect isolation (no state bleed between files), parallelism, and no cold boot per file. Point --runner at examples/askr-test.php for PHPUnit/Pest, or omit it to run files directly. Exits non-zero if any file fails.

¶8. File uploads that stream to disk (0.4.0)

multipart/form-data is streamed, not buffered: each file part goes straight to a temp file, so a large upload costs constant memory (a 32 MB upload no longer holds 32 MB in RAM), and form fields are parsed to POST params. Askr hands PHP the $_FILES-shaped metadata and examples/laravel-worker.php rebuilds them as Laravel UploadedFiles in test mode — so uploads work in worker mode:

$request->file('avatar')->store('avatars');   // just works
$request->input('name');                       // multipart fields too

Temp files land under $TMPDIR/askr-uploads and are removed after each request. The --max-body-size limit is enforced on the stream (413 above it); set PHP's upload_max_filesize/post_max_size via [worker] ini if your app checks them.

¶9. Compression, logging & observability (0.4.1)

• Response compression — compressible responses are compressed in Rust, negotiating br (preferred) or gzip from Accept-Encoding (often 5–10× fewer bytes). Dynamic, cached, and small static responses; large files keep streaming. Automatic — no config.

• Access log — --access-log <path|-> / [server] access_log writes one JSON line per request (ts, ip, method, path, status, bytes, dur_ms).

• Prometheus — GET /metrics on the admin plane exposes Prometheus text format (requests, status classes, PHP-vs-I/O seconds, cache hits/misses/evictions, in-flight + live workers, latency histogram):

  scrape_configs:
    - job_name: askr
      static_configs: [{ targets: ["127.0.0.1:9000"] }]