Fire-and-forget¶
Fire-and-forget is a pattern where a task is dispatched and the caller does not wait for its result, does not check for errors, and does not expect a return value. The caller continues execution immediately after dispatching.
Common uses in PHP include sending emails, dispatching jobs to a queue, logging, analytics events, and cache invalidation: any side-effect that should not delay the main response.
In synchronous PHP, fire-and-forget is often approximated by closing the HTTP response early, fastcgi_finish_request(), and continuing processing, or by pushing work onto a message queue (Redis, RabbitMQ, SQS). With fibers or async runtimes (ReactPHP, AMPHP, Revolt), true non-blocking dispatch becomes possible.
The risk of fire-and-forget is silent failure: if the dispatched task errors, the caller has no way to detect or recover from it. Robust implementations route failures to a dead-letter queue or structured log.
<?php
// Approximated in sync PHP via fastcgi_finish_request()
ob_start();
echo 'Response sent to client.';
$size = ob_get_length();
header('Content-Length: ' . $size);
header('Connection: close');
ob_end_flush();
flush();
fastcgi_finish_request(); // client receives the response here
// Work runs after the client is disconnected
dispatch_slow_email($user);
// With a queue (true fire-and-forget)
$queue->push(new SendEmailJob($user));
// caller does not wait — queue worker handles it asynchronously
?>
See also fastcgi_finish_request.
Related : Async, Asynchronous, Event Loop, Message Queue, Fibers, Polling, Side Effect
