Statsite is a metrics aggregation server. Statsite is based heavily on Etsy's StatsD https://github.com/etsy/statsd, and is wire compatible. Statsite is designed to be both highly performant, and very flexible. To achieve this, it implements the stats collection and aggregation in pure C, using an event loop to be extremely fast. This allows it to handle hundreds of connections, and millions of metrics. After each flush interval expires, statsite performs a fork/exec to start a new stream handler invoking a specified application. Statsite then streams the aggregated metrics over stdin to the application, which is free to handle the metrics as it sees fit.