Munin-Rails-Plugins

Collection of Concise Munin plugins for Rails server environments. This will make monitoring your rails app a piece of cake.

This project contains munin plugins that not only work in munin, but are also concise (see references). Most things in this repository rely heavily on the request-log-analyzer gem. The project has recenly been converted into a gem. If you are looking for the loose scripts, please checkout: github.com/barttenbrinke/munin-plugins-rails/tree/master/munin.

What’s in the box?

  • passenger_memory_stats - Munin plugin to monitor the memory usage of passenger application servers.

  • pasenger_queue - Montoring of passenger queue lenth.

  • passenger_status - Running, active and maximum number of passenger instances as well as sessions.

  • rails_database_time - Min, avg, max of database times.

  • rails_request_duration - Min, avg, max of the total request durations.

  • rails_request_error - Application errors and process blocker counters.

  • rails_requests - Get, put, post and delete requests.

  • rails_view_render_time - Min, avg and max view render times.

For screenshots, head over to: barttenbrinke.github.com/munin-plugins-rails/

Installation

Installing should be as easy as

$ gem install munin-plugins-rails

After that you have two options. You can add the passenger plugins that will monitor the server as a whole by running:

$ sudo request-log-analyzer-munin install

This will create the necessary symlinks in /etc/munin/plugins and create reasonable configurations in /etc/munin/plugin-conf.d/*

  • munin_passenger_memory_stats

  • munin_passenger_queue

  • munin_passenger_status

Which you can customize as needed. Please note that passenger-memory-status currently only works on Linux (bit.ly/krKO2x).

The other option is to add a specific application’s logfile. To do this, run:

$ sudo request-log-analyzer-munin add <app_name> <path_to_log_file>

* app_name: this will be the prefix for the graphs and the munin plugins so it should be a valid identifier (/[A-Za-z0-9_]*/).
* path_to_log_file: this is the path to the log file against which request-log-analyzer will run

After running this command you’ll have appropriate symlinks in /etc/munin/plugins and a set of configuration files in /etc/munin/plugin-conf.d:

  • app_name_munin_rails_database_time

  • app_name_munin_rails_request_duration

  • app_name_munin_rails_request_error

  • app_name_munin_rails_requests

  • app_name_munin_rails_view_render_time

For more detailed information, see the documentation embedded in the plugins. Remember to restart munin-node.

$ sudo /etc/init.d/munin-node restart

Troubleshooting

  • Specify the format of your logfile in the munin conf (i.e: env.log_format rails3).

  • sudo gem install request-log-analyzer

  • Check if the paths in the plugin configuration are correct.

  • Use munin-run to test the plugin with the --debug option.

  • Make sure the specified user is allowed to write to /tmp and read your rails logfile.

If you encounter performance problems with your app, please take a look at the request-log-analyzer wiki on examples on how to drill down to the core of your problem. If you want to hire an expert, please visit us at railsdoctors.com or mail me at: [email protected]

Happy monitoring!

Additional information