Fluentd is an open-source log collector that is intended to help companies gain a better understanding of their data.
It unifies all parts of processing log data, including collecting, filtering, buffering, and outputing logs. This is made possible because all data is structured in JSON as much as possible.
It also utilizes a flexible plugin system, so users can connect different data sources and outputs. Currently there are over 500 community-made plugins that can be used.
Fluentd was created in 2011 by Sadayuki “Sada” Furuhashi, who is the co-founder of Treasure Data, one of the main sponsors of the project. It became a CNCF project in 2016 and reached Graduation status in 2019.
It is now in use at over 5,000 companies, including AWS, Microsoft, and Nintendo, and it has over 12,000 stars on GitHub.
There is also a subproject called Fluent Bit, which is designed to be more lightweight (it has 450 KB of memory compared to Fluentd’s 40 MB).
The most recent release at the time of this writing is 1.16.1, which was released in April 2023.