Fluent Bit is a lightweight, high-performance telemetry agent written in C that collects, processes, and forwards logs, metrics, and traces from any source to any destination. It is part of the Fluentd ecosystem and operates as a CNCF graduated project. The agent is designed for minimal resource consumption while maintaining high throughput, making it suitable for deployment across diverse environments including Linux, BSD, macOS, Windows, and embedded systems.
The repository demonstrates substantial production adoption, with the README documenting over 10 million daily deployments and surpassing 15 billion total downloads.
The architecture centers on a pluggable design supporting over 70 built-in plugins across input, filter, and output categories. Key technical features include SQL stream processing capabilities for analytics and transformations, built-in TLS/SSL support with async I/O for secure networking, and HTTP/Prometheus endpoints for exposing internal metrics. The extensibility model allows plugin development in C, filter creation in Lua, and output plugin development in Go. The unified processing pipeline handles logs, metrics, and traces through a single architecture.
Development follows a fast-paced cycle with major releases every three to four months, with the active master branch currently focused on version 5.0 development. The project maintains version-specific maintenance timelines documented in MAINTENANCE.md and tracks upcoming work through a public roadmap. Installation options span Linux packages for Debian, Ubuntu, and RHEL distributions, Docker images, and Windows binaries, with source builds supported through CMake, Flex, Bison, and standard development headers.
The project integrates with major cloud and data infrastructure services including AWS CloudWatch, Elasticsearch, Kafka, and S3. Cross-repository contributor analysis links Fluent Bit to microsoft/vscode, microsoft/typescript, and rust-lang/rust, indicating shared maintainer involvement across these ecosystems. The project operates under the Apache License v2.0 and maintains community engagement through Slack channels and social media presence.
