# Process Exporter Metrics

[Prometheus Node Exporter](https://github.com/prometheus/node_exporter) is a popular way to collect system level metrics from operating systems, such as CPU / Disk / Network / Process statistics. Fluent Bit 2.2 onwards includes a process exporter plugin that builds off the Prometheus design to collect process level metrics without having to manage two separate processes or agents.

The Process Exporter Metrics plugin implements collecting of the various metrics available from [the 3rd party implementation of Prometheus Process Exporter](https://github.com/ncabatoff/process-exporter) and these will be expanded over time as needed.

**Important note:** All metrics including those collected with this plugin flow through a separate pipeline from logs and current filters do not operate on top of metrics.

This plugin is only supported on Linux based operating systems as it uses the `proc` filesystem to access the relevant metrics.

macOS does not have the `proc` filesystem so this plugin will not work for it.

## Configuration

| Key                       | Description                                                                                                                                                                                                                                                                                         | Default                                                                  |
| ------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------ |
| scrape\_interval          | The rate at which metrics are collected.                                                                                                                                                                                                                                                            | 5 seconds                                                                |
| path.procfs               | The mount point used to collect process information and metrics. Read-only is enough                                                                                                                                                                                                                | /proc/                                                                   |
| process\_include\_pattern | regex to determine which names of processes are included in the metrics produced by this plugin                                                                                                                                                                                                     | It is applied for all process unless explicitly set. Default is `.+`.    |
| process\_exclude\_pattern | regex to determine which names of processes are excluded in the metrics produced by this plugin                                                                                                                                                                                                     | It is not applied unless explicitly set. Default is `NULL`.              |
| metrics                   | To specify which process level of metrics are collected from the host operating system. These metrics depend on `/proc` fs. The actual values of metrics will be read from `/proc` when needed. cpu, io, memory, state, context\_switches, fd, start\_time, thread\_wchan, thread depend on procfs. | `cpu,io,memory,state,context_switches,fd,start_time,thread_wchan,thread` |

## Metrics Available

| Name              | Description                                        |
| ----------------- | -------------------------------------------------- |
| cpu               | Exposes CPU statistics from `/proc`.               |
| io                | Exposes I/O statistics from `/proc`.               |
| memory            | Exposes memory statistics from `/proc`.            |
| state             | Exposes process state statistics from `/proc`.     |
| context\_switches | Exposes context\_switches statistics from `/proc`. |
| fd                | Exposes file descriptors statistics from `/proc`.  |
| start\_time       | Exposes start\_time statistics from `/proc`.       |
| thread\_wchan     | Exposes thread\_wchan from `/proc`.                |
| thread            | Exposes thread statistics from `/proc`.            |

## Threading

This input always runs in its own [thread](https://docs.fluentbit.io/manual/3.2/administration/multithreading#inputs).

## Getting Started

### Simple Configuration File

In the following configuration file, the input plugin \_process\_exporter\_metrics collects \_metrics every 2 seconds and exposes them through our [Prometheus Exporter](https://docs.fluentbit.io/manual/3.2/pipeline/outputs/prometheus-exporter) output plugin on HTTP/TCP port 2021.

```
# Process Exporter Metrics + Prometheus Exporter
# -------------------------------------------
# The following example collect host metrics on Linux and expose
# them through a Prometheus HTTP end-point.
#
# After starting the service try it with:
#
# $ curl http://127.0.0.1:2021/metrics
#
[SERVICE]
    flush           1
    log_level       info

[INPUT]
    name            process_exporter_metrics
    tag             process_metrics
    scrape_interval 2

[OUTPUT]
    name            prometheus_exporter
    match           process_metrics
    host            0.0.0.0
    port            2021
```

You can see the metrics by using *curl:*

```bash
curl http://127.0.0.1:2021/metrics
```

### Container to Collect Host Metrics

When deploying Fluent Bit in a container you will need to specify additional settings to ensure that Fluent Bit has access to the process details. The following `docker` command deploys Fluent Bit with a specific mount path for `procfs` and settings enabled to ensure that Fluent Bit can collect from the host. These are then exposed over port 2021.

```
docker run -ti -v /proc:/host/proc:ro \
               -p 2021:2021        \
               fluent/fluent-bit:2.2 \
               /fluent-bit/bin/fluent-bit \
                         -i process_exporter_metrics -p path.procfs=/host/proc  \
                         -o prometheus_exporter \
                         -f 1
```

## Enhancement Requests

Development prioritises a subset of the available collectors in the [the 3rd party implementation of Prometheus Process Exporter](https://github.com/ncabatoff/process-exporter), to request others please open a Github issue by using the following template:\
\
\- [in\_process\_exporter\_metrics](https://github.com/fluent/fluent-bit/issues/new?assignees=\&labels=\&template=feature_request.md\&title=in_process_exporter_metrics:%20add%20ABC%20collector)