cpu1sec

A munin plugin to collect CPU statistic data once every second.

How

The plugin uses data available in procfs to display CPU idle/iowait/user/system/... data. Statistics are read once per second and written to a cachefile, whenever munin asks for the data, the content of the cachefile is send.

Usage

Compile (or load a released binary, if one is there) and put the binary somewhere. Then link it into the munin plugins dir.

When first called without arguments, cpu1sec will spawn itself into the background to gather data. This can also be triggered by calling it with the acquire & parameter.

Detailed graphs

Per default this plugin will only produce a "total" graph, similar to what the default cpu plugin from munin does (though in much higher resolution, obviously).

The plugin can produce the graphs per CPU/core on the system. Then the view "total" will be the front, when you click it, you get a detail graph of every CPU core on the system.

To activate this, set the environment variable cpudetail to 1, say in /etc/munin/plugin-conf.d/cpu1sec.conf put

[cpu1sec]
env.cpudetail=1

Filesize

Note that every graph has 10 datasets, and each dataset uses ~11MB on disk. If you have many cores, enabling cpudetail may easily run you out of disk space!

Installation

1. You need a rust environment setup. If you have none yet, please follow the instructions at either the Rust Lang Get Started Page or rustup.rs
2. Download or clone this repo
3. Inside your copy, run cargo build --release --target x86_64-unknown-linux-musl
4. Copy target/x86_64-unknown-linux-musl/release/munin-cpu1sec to a useful place on your system and link it to /etc/munin/plugins/cpu1sec.
5. If you want the detailed CPU graphs, put the neccessary lines (see above) into munins plugin config.
6. Restart munin-node (on Debian: systemctl munin-node restart)

Local build

Use cargo build as usual. Note that the release build contains much less logging code than the debug build, so if you want to find out why something does not work as planned, ensure to use a debug build (cargo build instead of cargo build --release).

Musl

Note that I build using musl, as I want fully static binaries. "Normal" rust link against libc, and that may carry symbols that aren't available everywhere (older versions). If you do not have that requirement, not using musl will be fine.

Packages

Note that they do not live up to distribution quality, but they do work for an easy install.

Debian package

A minimal Debian package can be build using cargo deb, provided that you installed this feature (cargo install cargo-deb).

RPM package

A minimal package for RPM based systems can be build using cargo generate-rpm, provided that you installed this feature (cargo install cargo-generate-rpm)