About

StatsD is developed by Etsy team and is written in node.js. It is a network daemon which listens on a predefined port for UDP packets that are send to it which describe different data metrics, aggregates them, and flushes the aggregated data through back end defined by the user.

The applications can feed any number of UDP packets in formats defined by statsD termed as buckets.

StatsD aggregates the data received over UDP and creates the result for the defined flush interval and sends it to the defined backend.

The default backend provided by statsD is graphite and it has options to choose the backend that may fit the application scenario.

Concepts

1. buckets: Each stat is in its own "bucket". They are not predefined anywhere. Buckets can be named anything that will translate to Graphite (periods make folders, etc)
2. values: Each stat will have a value. How it is interpreted depends on modifiers
3. flush: After the flush interval timeout (default 10 seconds), stats are munged and sent over to Graphite or any other backend choosen.

Supported Backends

1. Graphite (graphite): An open-source time-series data store that provides visualization through a web-browser.
2. Console (console): Outputs the received metrics to stdout (see what's going on during development).
3. Repeater (repeater): Utilizes the packet emit API to forward raw packets retrieved by StatsD to multiple backend StatsD instances.
4. More options available as separate packges can be found here

Open Source

fork StatsD from here: http://github.com/etsy/statsd