Collector

Process Collector

The Python client automatically exports metrics about process CPU usage, RAM, file descriptors and start time. These all have the prefix process, and are only currently available on Linux.

The namespace and pid constructor arguments allows for exporting metrics about other processes, for example:

ProcessCollector(namespace='mydaemon', pid=lambda: open('/var/run/daemon.pid').read())

Platform Collector

The client also automatically exports some metadata about Python. If using Jython, metadata about the JVM in use is also included. This information is available as labels on the python_info metric. The value of the metric is 1, since it is the labels that carry information.

Disabling Default Collector metrics

By default the collected process, gc, and platform collector metrics are exported. If this information is not helpful, it can be disabled using the following:

import prometheus_client

prometheus_client.REGISTRY.unregister(prometheus_client.GC_COLLECTOR)
prometheus_client.REGISTRY.unregister(prometheus_client.PLATFORM_COLLECTOR)
prometheus_client.REGISTRY.unregister(prometheus_client.PROCESS_COLLECTOR)

API Reference

ProcessCollector

ProcessCollector(namespace='', pid=lambda: 'self', proc='/proc', registry=REGISTRY)

Collects process metrics from /proc. Only available on Linux.

Parameter	Type	Default	Description
`namespace`	`str`	`''`	Prefix added to all metric names, e.g. `'mydaemon'` produces `mydaemon_process_cpu_seconds_total`.
`pid`	`Callable[[], int or str]`	`lambda: 'self'`	Callable that returns the PID to monitor. `'self'` monitors the current process.
`proc`	`str`	`'/proc'`	Path to the proc filesystem. Useful for testing or containerised environments with a non-standard mount point.
`registry`	`CollectorRegistry`	`REGISTRY`	Registry to register with. Pass `None` to skip registration.

Metrics exported:

Metric	Description
`process_cpu_seconds_total`	Total user and system CPU time in seconds.
`process_virtual_memory_bytes`	Virtual memory size in bytes.
`process_resident_memory_bytes`	Resident memory size in bytes.
`process_start_time_seconds`	Start time since Unix epoch in seconds.
`process_open_fds`	Number of open file descriptors.
`process_max_fds`	Maximum number of open file descriptors.

The module-level PROCESS_COLLECTOR is the default instance registered with REGISTRY.

PlatformCollector

PlatformCollector(registry=REGISTRY, platform=None)

Exports Python runtime metadata as a python_info gauge metric with labels.

Parameter	Type	Default	Description
`registry`	`CollectorRegistry`	`REGISTRY`	Registry to register with. Pass `None` to skip registration.
`platform`	module	`None`	Override the `platform` module. Intended for testing.

Labels on python_info: version, implementation, major, minor, patchlevel. On Jython, additional labels are added: jvm_version, jvm_release, jvm_vendor, jvm_name.

The module-level PLATFORM_COLLECTOR is the default instance registered with REGISTRY.

GCCollector

GCCollector(registry=REGISTRY)

Exports Python garbage collector statistics. Only active on CPython (skipped silently on other implementations).

Parameter	Type	Default	Description
`registry`	`CollectorRegistry`	`REGISTRY`	Registry to register with.

Metrics exported:

Metric	Description
`python_gc_objects_collected_total`	Objects collected during GC, by generation.
`python_gc_objects_uncollectable_total`	Uncollectable objects found during GC, by generation.
`python_gc_collections_total`	Number of times each generation was collected.

The module-level GC_COLLECTOR is the default instance registered with REGISTRY.