Fluent Bit is an open-source log processor and forwarder. It's part of the Fluentd project, a Cloud Native Computing Foundation (CNCF) project.
Fluent Bit is designed for high performance, with a low memory footprint, and it's built to collect data/logs from different sources, enrich this data, and send it to various outputs.
It's generally used in scenarios where log delivery is critical, such as in Kubernetes environments or embedded systems. The software provides a pluggable architecture that allows users to customize their data pipelines according to their needs. As of my last update in September 2021, Fluent Bit is maintained by Treasure Data, Inc.
Logging is a software development practice in which application data about events, warnings and errors is being saved in an organized manner that allows for a better understanding of that system's operations and a quicker incidents response.
Some of the many reasons for using logging tools: