v. 1.35.4

Status API§

Unit collects information about the loaded language models, as well as instance- and app-wide metrics, and makes them available via the GET-only /status section of the control API:

Option	Description
modules	Object; lists currently loaded language modules.
connections	Object; lists per-instance connection statistics.
requests	Object; lists per-instance request statistics.
applications	Object; each option item lists per-app process and request statistics.

Example:

{
    "modules": {
        "python": [
            {
                "version": "3.12.3",
                "lib": "/opt/unit/modules/python.unit.so"
            },
            {
                "version": "3.8",
                "lib": "/opt/unit/modules/python-3.8.unit.so"
            }
        ],

        "php": {
           "version": "8.3.4",
           "lib": "/opt/unit/modules/php.unit.so"
        }
    },

    "connections": {
        "accepted": 1067,
        "active": 13,
        "idle": 4,
        "closed": 1050
    },

    "requests": {
        "total": 1307
    },

    "applications": {
        "wp": {
            "processes": {
                "running": 14,
                "starting": 0,
                "idle": 4
            },

            "requests": {
                "active": 10
            }
        }
    }
}

Each item in the modules object lists one of the currently loaded language modules, the installed version (or versions) of the module, and the path to the module file:

Option	Description
name	String; language module name.
version	String; language module version. If multiple versions are loaded, the list contains multiple items.
lib	String; path to the language module file.

The connections object offers the following Unit instance metrics:

Option	Description
accepted	Integer; total accepted connections during the instance’s lifetime.
active	Integer; current active connections for the instance.
idle	Integer; current idle connections for the instance.
closed	Integer; total closed connections during the instance’s lifetime.

Example:

"connections": {
    "accepted": 1067,
    "active": 13,
    "idle": 4,
    "closed": 1050
}

Note

For details of instance connection management, refer to Settings.

The requests object currently exposes a single instance-wide metric:

Option	Description
total	Integer; total non-API requests during the instance’s lifetime.

Example:

"requests": {
    "total": 1307
}

Each item in applications describes an app currently listed in the /config/applications section:

Option	Description
processes	Object; lists per-app process statistics.
requests	Object; similar to /status/requests, but includes only the data for a specific app.

Example:

"applications": {
    "wp": {
        "processes": {
            "running": 14,
            "starting": 0,
            "idle": 4
        },

        "requests": {
            "active": 10
        }
    }
}

The processes object exposes the following per-app metrics:

Option	Description
running	Integer; current running app processes.
starting	Integer; current starting app processes.
idle	Integer; current idle app processes.

Example:

"processes": {
    "running": 14,
    "starting": 0,
    "idle": 4
}

Note

For details of per-app process management, refer to Process management.

PHP Status§

For PHP applications, Unit provides detailed statistics about the PHP runtime, including opcache performance, JIT status, request counters, garbage collection, and memory usage via the /status/applications/<app-name>/php endpoint:

$ curl http://localhost:8443/status/applications/myapp/php

Example response:

{
    "opcache": {
        "enabled": 1,
        "hits": 12345,
        "misses": 234,
        "cached_scripts": 89,
        "memory_used": 4194304,
        "memory_free": 131072,
        "interned_strings_used": 262144,
        "interned_strings_free": 0
    },

    "jit": {
        "enabled": 0,
        "buffer_size": 0,
        "memory_used": 0
    },

    "requests": {
        "total": 5000,
        "active": 2,
        "rejected": 0
    },

    "gc": {
        "runs": 15,
        "last_run_time": 1234567890
    },

    "memory": {
        "peak": 8388608,
        "current": 2097152
    }
}

The opcache object provides statistics from the Zend OPcache:

Option	Description
enabled	Integer; `1` if opcache is enabled, `0` otherwise. In PHP 8.5+, opcache is always enabled.
hits	Integer; total cache hits during the application’s lifetime.
misses	Integer; total cache misses during the application’s lifetime.
cached_scripts	Integer; number of scripts currently cached in opcache.
memory_used	Integer; opcache memory usage in bytes.
memory_free	Integer; free opcache memory in bytes.
interned_strings_used	Integer; memory used by interned strings in bytes.
interned_strings_free	Integer; free memory for interned strings in bytes.

The jit object provides information about the JIT compiler:

Option	Description
enabled	Integer; `1` if JIT is enabled, `0` otherwise.
buffer_size	Integer; JIT buffer size in bytes.
memory_used	Integer; JIT memory usage in bytes.

Note

JIT statistics are available in PHP 8.0+. JIT must be enabled via the opcache.jit INI setting.

The requests object provides per-application request counters:

Option	Description
total	Integer; total requests processed by the application.
active	Integer; currently active requests.
rejected	Integer; total rejected requests.

The gc object provides garbage collection statistics:

Option	Description
runs	Integer; total GC runs during the application’s lifetime.
last_run_time	Integer; timestamp of the last GC run.

The memory object provides memory usage statistics from the Zend allocator:

Option	Description
peak	Integer; peak memory usage in bytes.
current	Integer; current memory usage in bytes.

Monitoring and Observability

PHP status metrics can be used for:

Performance monitoring: Track opcache hit rates to ensure efficient caching
Capacity planning: Monitor memory usage trends across workers
Debugging: Identify GC frequency and memory pressure issues
Prometheus integration: Export metrics for Grafana dashboards

Example Prometheus metrics export:

unit_php_opcache_hits{app="myapp"} 12345
unit_php_opcache_misses{app="myapp"} 234
unit_php_memory_peak{app="myapp"} 8388608
unit_php_requests_total{app="myapp"} 5000

Configuration

To enable opcache for PHP applications, configure INI options:

{
    "type": "php",
    "root": "/var/www/myapp",
    "options": {
        "admin": {
            "opcache.enable": "1",
            "opcache.memory_consumption": "128",
            "opcache.max_accelerated_files": "10000"
        }
    }
}

For JIT support (PHP 8.0+):

{
    "options": {
        "admin": {
            "opcache.jit": "1255",
            "opcache.jit_buffer_size": "128M"
        }
    }
}