Procfs plugin

Collects processes and system-related metrics by reading the proc virtual filesystem on Linux based operating systems.

Requirements

• Linux operating system.
• Read access to the /proc virtual file system. Depending on the mount options, some privileges might be needed.

Metrics

There are various information collected by this plugin relative to Kernel, CPU, memory and processes:

• *Context switches: Operation allowing a single CPU to manage multiple processes efficiently, involves saving the state of a currently running process and loading the state of another process, enabling multitasking and optimal CPU utilization.
• *Forks: When a process creates a copy of itself.

Attributes

Kind

The kind of the memory is the allocated memory space reserved by the system or the hardware (https://man7.org/linux/man-pages/man5/proc_pid_status.5.html):

The kind of the CPU time delta is the average CPU time spent by various tasks:

cpu_state

The CPU states is an attribute that indicates the kind of cpu time that is measured:

Configuration

Here is a configuration example of the plugin. It is composed of different sections. Each section can be enabled or disabled with the enabled boolean parameter.

Kernel metrics

To active the plugin to collect metrics relative to the kernel utilization:

[plugins.procfs.kernel]
# `true` to enable the monitoring of kernel information.
enabled = true
# How frequently should the kernel information be flushed to the rest of the pipeline.
poll_interval = "5s"

Memory metrics

Moreover, you can collect more or less precise metrics on memory consumption, by setting the level of detail you want to extract from /proc/meminfo file (refers to https://man7.org/linux/man-pages/man5/proc_meminfo.5.html). The names of the collected metrics are converted to snake case (MemTotal becomes mem_total):

[plugins.procfs.memory]
# `true` to enable the monitoring of memory information.
enabled = true
# How frequently should the memory information be flushed to the rest of the pipeline.
poll_interval = "5s"
# The entry to parse from `/proc/meminfo`.
metrics = [
    "MemTotal",
    "MemFree",
    "MemAvailable",
    "Cached",
    "SwapCached",
    "Active",
    "Inactive",
    "Mapped",
]

Process metrics

To enable process monitoring, you need to set the metrics collect policy via a strategy:

• watcher: Default strategy of system watcher to collect new processes, whatever it may be.
• event: Set this parameter to collect the process that acts as an internal event of ALUMET.

[plugins.procfs.processes]
# `true` to enable the monitoring of processes.
enabled = true
# Watcher refresh interval.
refresh_interval = "2s"
# `true` to watch for new processes, `false` to only react to ALUMET events.
strategy = "watcher"

Group process metrics

Also, you can monitor groups of processes, i.e. processes defined by common characteristics. The available filters are pid (process id), ppid (parent process id) and exe_regex (a regular expression that must match the process executable path):

[[plugins.procfs.processes.groups]]
# Only monitor the processes whose executable path matches this regex.
exe_regex = ""
# How frequently should the processes information be refreshed.
poll_interval = "2s"
# How frequently should the processes information be flushed to the rest of the pipeline.
flush_interval = "4s"

More information

Procfs Access

To grant the required access to retrieve all metrics properly by reading /proc filesystem, you need to configure the parameter hidepid by editing the configuration file /proc/mounts. This setting is a mount option for the /proc filesystem, that is used to control the visibility of processes to unprivileged users. In this way, it can define the access restriction to /proc/<pid>/ directories, and therefore visibility of processes stats. By default, the hidepid parameter is generally set to allow the full access to /proc/<pid>/ directories on Linux systems. If your system was configured differently, you must edit the configuration file /proc/mounts, and root privileges may be required for this operation.

mount -o remount,hidepid=0 -t proc proc /proc

Which results in a remount on the /proc mount point with full visibility of all user processes on the system. If you want to set a precise visibility, here are its available configuration values: