Deprecated, see here

cpu-throughput

Munin plugin for measuring cpu throughput, as a bash shell script

On load testing a web server, I noticed huge variation in VPS latency but couldn't find any real cause, so wrote this to check the cpu throughput.

The idea is:

• Run a cpu-bound, fixed task and measure the elapsed time. In this case it's the time taken to do a sha512sum of a large block of data from memory. Output sequential measurements to a log over an extended period of time
• Every munin collection period, calculate the average and maximum measurements, display on a graph, and delete the log

NOTE: This currently only exercises 1 CPU core, so may not be as useful on multi-core machines

Dependencies

• munin
• bash
• bc
• od
• date
• sha512sum

How to use

1. Clone the repo in /root/

2. Link the plugin.sh file to your plugins, for example:

ln -s /root/cpu-throughput/plugin.sh /etc/munin/plugins/vps

3. Configure the plugin to run as root (not actually required, but I cloned as root):

/etc/munin/plugin-conf.d/munin-node

[vps]
user root

5. service munin-node restart

6. Run the cpu-throughput.sh script:

./cpu-throughput.sh [1200] &

• optionally provide a run time in seconds, by default it runs for a minimum of 20 minutes and quits