Radar is a monitoring tool that tries to make things simple and easy. Radar is not an advanced monitoring tool and you may not find all features that you may find in other monitoring solutions because Radar’s philosophy is based heavily on two ideas :

  • Simplicity : Both user-interface and source code are intended to be as simple and clean as possible. The code isn’t designed to grow indefinitely mainly because by limiting its scope, its behaviour can be better controlled, tested and understood. The code is designed to be understood by anyone who has some Python and OOP knowledge. Its main ideas are described later in the internals section of this document.
  • Extensibility : As you will see later Radar is not focused on any particular resource monitoring. Instead it allows you to integrate any custom designed checks to verify any resource that you want. This does not only applies to IT infrastructure, you could for example read data from a sensor that is attached to a PC or device that is capable of running the Python interpreter.

Once you get the Radar server up and running any number of clients may connect and after a user-defined interval they will be constantly polled. The following diagram shows the big picture how Radar operates :


So what can you really do with Radar ? Here are some ideas :

  • Notifications : This is a typical use. Notify any of your defined contacts if something is not performing as expected. You can notify by email, sms or maybe put data in a queue and have another process take that responsibility. You could also notify through a real time messaging system like XMPP.
  • Graphing tool : Each time you receive data from a check you can add that information to a database (like RRDtool) and then generate graphs. You can get trends of your resources this way.
  • Take an advanced action : Suppose that you run a cluster of servers on a cloud-based provider. Then by inspecting the replies of your checks, you can write a plugin to add/remove servers on demand, if you get for example that the amount of requests/sec. that a server is processing are exceeded.

Any of these ideas requires that you write a plugin for it, Radar does not include any built-in functionality and these tasks are delegated to plugins. You can take a look how to develop checks and plugins on the following sections of this document. Don’t panic ! A lot of effort has been put to make these tasks as simple as possible, so keep reading the docs.