Metrics Plugin

Prometheus-compatible metrics exporter for monitoring server performance and tracking custom application metrics. The plugin supports Counter, Gauge, Histogram, and Summary metric types.

Installation

$ composer require phpstreamserver/metrics

Usage Example

server.php

<?php

require __DIR__ . '/vendor/autoload.php';

use PHPStreamServer\Core\Server;
use PHPStreamServer\Core\Worker\SupervisedWorker;
use PHPStreamServer\Plugin\Metrics\MetricsPlugin;
use PHPStreamServer\Plugin\Metrics\RegistryInterface;
use Revolt\EventLoop;

$server = new Server();

$server->addPlugin(
    new MetricsPlugin(listen: '0.0.0.0:8081'),
);

$server->addWorker(
    new SupervisedWorker(
        name: 'Worker',
        count: 2,
        onStart: function (SupervisedWorker $worker): void {
            $registry = $worker->container->getService(RegistryInterface::class);

            $counter = $registry->registerCounter(
                namespace: 'app',
                name: 'test_counter',
                help: 'This is a test counter',
                labels: ['pid'],
            );

            EventLoop::repeat(1, function () use ($counter) {
                $counter->inc(['pid' => (string) \posix_getpid()]);
            });
        },
    ),
);

exit($server->run());

Built-in Metrics

PHPStreamServer registers these metrics automatically when the Metrics plugin is installed and registered. HTTP and Scheduler metrics are included when their corresponding plugins are also installed and registered.

Metric	Labels	Description
phpss_supervisor_workers	none	Current number of registered workers.
phpss_supervisor_processes	none	Current number of running processes.
phpss_supervisor_worker_reloads_total	none	Total number of worker reloads.
phpss_supervisor_process_crashes_total	none	Total number of process crashes.
phpss_supervisor_process_memory_bytes	pid	Memory usage of each process in bytes.
phpss_http_requests_total	status	Total number of handled HTTP requests.
phpss_http_request_duration_seconds	status	HTTP request duration.
phpss_scheduler_tasks	none	Current number of registered tasks.
phpss_scheduler_task_runs_total	none	Total number of scheduled task runs.

Plugin Configuration

🧩 MetricsPlugin

Plugin class: MetricsPlugin

Parameter	Type	Default	Description
listen	string|Listen	required	The address on which the metrics server listens. Metrics are exposed at /metrics.