collectd-softirqs

collectd-softirqs is a Python plugin for Collectd that measures the rate at which the Linux kernel handles softirqs.

Install

1. Deploy the softirqs.py plugin into collectd's Python plugin directory (e.g. /usr/lib/collectd/plugins/python)
2. Configure the plugin (see below)
3. Restart collectd

Configuration

Add the following to your collectd configuration file:

<LoadPlugin python>
    Globals true
</LoadPlugin>
    
<Plugin python>
    ModulePath "/usr/lib/collectd/plugins/python"
    Import "softirqs"

    <Module softirqs>
        Verbose false
    </Module>
</Plugin>

Options

The following options may be specified in the Module configuration stanza:

Option	Type	Default	Description
Softirq	String	-	Select this softirq to be collected (may appear multiple times)
IgnoreSelected	Boolean	False	If this is set to true, all selected softirqs are ignored and all others are collected
Verbose	Boolean	False	Enable verbose logging (not recommended)

How it works

The collectd-softirqs plugin is very similar to the Collectd's builtin IRQ plugin. It works by parsing the /proc/softirqs file to extract data about the number of softirqs handled by the kernel since boot time.

Manual run

You can run collectd-softirqs from the command line as a simple python script. It will output something like this and exit immediately:

$ python softirqs.py 
HRTIMER:4949
SCHED:1834967
BLOCK_IOPOLL:21
NET_TX:2920
RCU:1985467
TIMER:2095671
HI:68181
NET_RX:936
TASKLET:2829290
BLOCK:93491

This could be useful to get an idea of the values the plugin parses and dispatches to collectd.

Graph example

This is an example graph (a mostly idle system) created using rrdgraph: