FAQ

FAQ

Is this a replacement for Laravel Queue or Symfony Messenger?

No — it is for apps that don't have one. Laravel and Symfony already own a worker loop and retry machinery; the BabelQueue adapters plug into those. InitPHP Queue is the equivalent runtime for a plain PHP / Slim / Mezzio app that has no such loop of its own.

What is the relationship to babelqueue/php-sdk?

The SDK defines the wire format (the canonical envelope, URN routing, validation, dead-letter annotation) and a publish-only Transport. It deliberately does not own a consumer loop. InitPHP Queue is that consumer loop for framework-less PHP, plus a database transport the SDK does not ship. It depends on the SDK and reuses its codec, so the two never drift. See Core Concepts.

Why route on a URN instead of a class name?

So the queue is polyglot and refactor-safe. A URN is a stable string any language can match on; a PHP class name is neither. See The Message Envelope.

Do I have to use the Producer / HandlerMap?

No. The Producer is a one-line convenience over EnvelopeCodec + a transport; HandlerMap is one implementation of HandlerResolver. You can publish raw envelopes yourself and back routing with your own container — see Producing Messages and Handlers & Routing.

Which transport should I pick?

If you already have a database and want zero new infrastructure, use PDO. For throughput, use Redis. For a real broker with routing, use RabbitMQ. The overview has a comparison table.

How are retries delayed?

The worker re-queues a failed message with a back-off delay from WorkerOptions::$backoff. PDO and Redis honour the delay natively; RabbitMQ applies retries immediately unless the delayed-message-exchange plugin is installed. See Retries & Dead-Letters.

Is delivery exactly-once?

No — it is at-least-once. A message can be delivered more than once (e.g. a worker crashes after handling but before acking). Make handlers idempotent.

Can a Go / Python / Node service consume what PHP produces (and vice-versa)?

Yes — that is the whole point. They share the canonical envelope and route on the same URN. See Interoperability.

How do I run a worker in production?

Run vendor/bin/queue work --bootstrap=worker.php --queue=... under a process supervisor (systemd, supervisord, a container restart policy), and set a maxJobs/memoryLimitMb limit so each worker exits and restarts with clean memory. See The Worker.

How do I stop a worker cleanly during a deploy?

Send SIGTERM (or SIGINT). With ext-pcntl installed, the worker finishes the in-flight message and then exits.

Does it need an extension for Redis?

No — predis/predis is a pure-PHP client. ext-redis (phpredis) is optional; see Transport: Redis.

Where do failed messages go, and can I replay them?

To a per-transport dead-letter destination (a *_failed table, a :failed list, or a .failed queue). Decode the stored envelope, drop the dead_letter block, reset attempts, and re-publish. See Retries & Dead-Letters.

What PHP versions are supported?

PHP 8.2, 8.3 and 8.4 are tested in CI.