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:

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
    },

    "telemetry": {
        "spans": {
            "exported": 1200,
            "failed": 0
        }
    },

    "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:

The connections object offers the following Unit instance metrics:

Example:

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

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

Example:

"requests": {
    "total": 1307
}

The telemetry object reports the health of the OpenTelemetry span exporter. It is omitted entirely unless Unit was built with OpenTelemetry support, the /config/settings/telemetry option is set, and the exporter was initialised successfully; its absence is how you tell telemetry is off rather than idle. An exporter that could not be built -- an unusable endpoint or protocol -- leaves the object absent despite the option being set, and reports the reason in the log. Its single spans member exposes two counters:

Both counters are cumulative since the exporter was last built, so changing any telemetry setting resets them to zero; re-applying an identical configuration does not. They count spans rather than export batches, and count only spans an export was attempted for: a span the sampling_ratio dropped appears in neither. Neither does a span the exporter discarded before attempting an export, which is what happens once the export queue fills behind a stalled collector -- so failed staying at zero does not by itself prove that nothing was lost.

A healthy pipeline shows exported rising while failed stays at zero. A rising failed means telemetry is being lost before it reaches the collector.

Example:

"telemetry": {
    "spans": {
        "exported": 1200,
        "failed": 0
    }
}

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

Example:

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

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

The processes object exposes the following per-app metrics:

Example:

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

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

{
    "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
    }
}

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

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

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