Running PHP Under RoadRunner: Concepts and Pitfalls

RoadRunner persists PHP worker processes across multiple requests instead of rebuilding all state each time.

What It Does

RoadRunner persists PHP worker processes across multiple requests instead of rebuilding all state each time. The following examples distinguish a normal use case, a boundary case and a practical application.

Requirements and Compatibility

PHP 8.x and a local test environment. Apply input validation, correct error handling and the requirements of any optional libraries.

The code focuses on the core concept. Production implementation may also need routes, validation, persistence, authorization or deployment tooling.

Example 1: Basic Behavior

Understand the primary operation and its inputs.

<?php
class RequestState { public int $count = 0; }
$state = new RequestState();
$state->count++;
echo $state->count; // In a persistent worker, state survives unless explicitly reset

Example 2: Another Case

Check failure behavior or a different execution path.

<?php
$requests = [['user' => 1], ['user' => 2]];
foreach ($requests as $request) { $context = []; $context['user'] = $request['user']; echo $context['user']; }

Practical Example: Putting It to Use

Apply the behavior in a small, controlled scenario.

<?php
$start = memory_get_usage(true);
for ($n = 0; $n < 10; $n++) { $temporary = str_repeat('x', 100); unset($temporary); }
echo memory_get_usage(true) - $start; // Monitor actual worker growth

Important Behavior and Edge Cases

Request-scoped state, static caches and resource handles can leak across users unless reset.

Comparison with Related Functions or Approaches

Common Beginner Mistakes

Key Takeaways

• RoadRunner persists PHP worker processes across multiple requests instead of rebuilding all state each time.
• Request-scoped state, static caches and resource handles can leak across users unless reset.
• Traditional PHP-FPM has a different request lifecycle and isolation model.

Before adapting these examples, verify the return values, test the failure paths and confirm that your application meets its security and environment requirements.