This is a collection of munin plugins for Phusion Passenger.

They give you graphs for things like:

• How many requests are waiting in the queue for a worker.
• How many requests each worker is currently handling.
• How much RAM each Passenger worker is using.
• How much CPU each Passenger worker is using.
• How many cumulative requests have been processed by each worker.
• How long each worker has been alive.
• How long each worker has been idle.

The plugins are written in Ruby and packaged as a gem, because if you're running Passenger, presumably you are comfortable with Ruby and its ecosystem. To install them, first install the gem, then add symlinks to your munin plugins directory as desired. You can run this to symlink all the plugins automatically:

munin_passenger-install /etc/munin/plugins

(Actually /etc/munin/plugins if the default, so you can leave it off if you like.)

You should also configure the plugins by adding a file at /etc/munin/plugin-conf.d/passenger with these contents:

[passenger_*]
user root
env.PASSENGER_ROOT /usr/sbin

The user root line is necessary because otherwise passenger-status will refuse to run. The second line should be whatever directory contains passenger-status.

Once installed, you will get graphs for most of the things passenger-status can tell you.

• Distinguish between different groups/supergroups, perhaps by having plugins like passenger_ram_ etc. so you can get them in separate graphs.

• Suppress the "helpful" passenger-status message about xmllint so it doesn't clutter the munin log, without suppressing all the rest of stderr.

You can run tests by saying rspec spec.

You can build a local copy of the gem by saying rake build, and install it with rake install.

After running rake build you can run vagrant up to build a machine running Passenger against a dummy Rails app, with this munin plugin included. It will install the most recent *.gem file in pkg. Then you can do to http://192.168.60.10:7778/ to see the graphs.

You can run scripts/make-bins.rb to regenerate the files in bin.

You can run scripts/load-test.sh to simulate load on the app. While that is running, do scripts/capture-passenger-status.sh to get some realish XML you can use as a test fixture or example.

If you have it installed, you can use xmllint --format - and xmllint --noblanks - to make Passenger's XML readable vs compact.

You can release a new version of the gem with rake release.

Copyright (c) 2018 by Paul A. Jungwirth. See LICENSE.txt for further details.