Jarmo is a simple StatsD-like server. This means that Jarmo can be used for stats aggregation similarly to StatsD.

However there are a few differences. Jarmo does not define any metric types, instead it expects data to be sent in a JSON format. Jarmo merely parses the received data as JSON and adds a timestamp to the data as it is received.

Jarmo runs a flush cycle, similarly to StatsD. Upon the end of each cycle, all the received data is flushed to reporters, which in StatsD terms are defined as backends.

Configuration

The available configuration is listed below:

  export default {
    reporters: [
      '../reporters/influxdb'
      // List the 'require':able paths of wanted reporters here...
    ],
    memoize:        false,  // Whether to 'cache' received data.
    port:           8000,   // Port to run the service on.
    flush_interval: 10000   // The interval between flushes (in milliseconds).
                            // If set to zero, received data will be flushed to
                            // reporters as soon as it is received.
  }

Reporter Configuration

Each reporter defines a name, for example our influxdb-reporter is simply called influxdb here. In order to pass configuration to initialize method of the reporter, we add the configuration object with the key influxdb to our configuration file, like so:

  export default {
    influxdb: {
      // reporter configuration for 'influxdb' goes here!
    },
    reporters: [
      '../reporters/influxdb'
    ],
    host: 'localhost'
  }

Reporter Interface

Reporters must be requireable using the NodeJS require. The exported module must have a flush function, which unsurprisingly is called each time data is to be flushed.

If a reporter defines an initialize function, it is called during the server initialization phase after reporters have been loaded. It is given the config hash keyed by its name in the server's configuration file.

Running

npm install && npm start

Sending Data

Jarmo expects simple JSON messages delivered via UDP.

echo "{\"foo\":\"bar\"}" | nc -u -w0 localhost 8000

Do note that Jarmo does not format your messages in any way. In fact it is the reporter that is responsible for extracting the required data from the JSON messages and reporting it to wherever.