[frsyuki]

We're also using Fluentd as well as original JSON-based logging libraries.

Fluentd deals with JSON-based logs. JSON is good for human facing interface because it is human readable and GREPable.

On the other side, Fluentd handles logs in MessagePack format internally. Msgpack is a serialization format compatible with JSON and can be an efficient replacement of JSON.

I wrote plugin for Fluentd that send those structured logs to Librato Metrics (https://metrics.librato.com/) which provides charting and dashboard features.

With Fluentd, our logs became program-friendly as well as human-firnedly.