README

An OPcache metrics collector for Prometheus Exporter in Laravel applications. This package collects OPcache memory usage, cache statistics, interned strings, JIT status, and configuration limits, exposing them in Prometheus format.

Requirements

Installation

Install via Composer:

composer require vntrungld/prometheus-exporter-opcache-collector

The package uses Laravel's auto-discovery, so the service provider will be automatically registered.

Configuration

Add the collector set to your prometheus-exporter configuration file (config/prometheus-exporter.php):

return [
    // ... other config options

    'collector_sets' => [
        \Vntrungld\PrometheusExporterOpcacheCollector\OpcacheCollectorSet::class,
        // ... other collector sets
    ],
];

Available Metrics

Up Status

Memory Usage

Cache Statistics

Interned Strings

JIT (PHP 8.0+)

These metrics are only available when JIT is present. They are silently skipped on PHP < 8.0.

Configuration Limits

These gauges expose OPcache configuration values, useful for computing utilization ratios in PromQL.

Example PromQL Queries

# Memory utilization %
opcache_used_memory_bytes / opcache_config_memory_limit_bytes * 100

# Script slots utilization %
opcache_cached_scripts / opcache_config_max_accelerated_files * 100

# Interned strings utilization %
opcache_interned_strings_used_bytes / opcache_config_interned_strings_buffer_bytes * 100

# Cache hit rate %
opcache_hits_total / (opcache_hits_total + opcache_misses_total) * 100

Example Output

# HELP opcache_up Whether OPcache is available.
# TYPE opcache_up gauge
opcache_up 1

# HELP opcache_used_memory_bytes The amount of used memory by OPcache.
# TYPE opcache_used_memory_bytes gauge
opcache_used_memory_bytes 67108864

# HELP opcache_free_memory_bytes The amount of free memory for OPcache.
# TYPE opcache_free_memory_bytes gauge
opcache_free_memory_bytes 67108864

# HELP opcache_cached_scripts The number of scripts cached by OPcache.
# TYPE opcache_cached_scripts gauge
opcache_cached_scripts 150

# HELP opcache_hits_total The total number of OPcache cache hits.
# TYPE opcache_hits_total counter
opcache_hits_total 50000

# HELP opcache_config_memory_limit_bytes The configured OPcache memory limit in bytes.
# TYPE opcache_config_memory_limit_bytes gauge
opcache_config_memory_limit_bytes 134217728

OPcache Configuration

For this collector to work, the OPcache extension must be enabled. Ensure your php.ini has:

opcache.enable=1

The collector uses PHP's built-in opcache_get_status() and opcache_get_configuration() functions. When OPcache is not available, the opcache_up metric reports 0 and all other metrics are silently skipped.

Testing

Run the test suite:

composer test

Or with PHPUnit directly:

vendor/bin/phpunit

Changelog

Please see the changelog for more information on what has changed recently.

Contributing

Please see contributing.md for details and a todolist.

Security

If you discover any security related issues, please email vn.trungld@gmail.com instead of using the issue tracker.

Credits

• vntrungld
• All Contributors

License

MIT. Please see the license file for more information.