fluent/fluent-bit

Free

Fast and Lightweight Logs, Metrics and Traces processor for Linux, BSD, OSX and Windows

FreeFree tier

Type

Open Source

Visit Website GitHub (38 stars)

About fluent/fluent-bit

Fluent Bit is a lightweight and high-performance Telemetry Agent designed to collect, process, and forward logs, metrics, and traces from any source to any destination. It is a graduated CNCF project under the Fluentd ecosystem. Fluent Bit features a pluggable architecture with over 70 built-in plugins for inputs, filters, and outputs, supports SQL stream processing for real-time analytics and transformations, and includes secure networking with built-in TLS/SSL and async I/O. It can be extended via C for plugins, Lua for filters, and Go for outputs. Fluent Bit runs on Linux, Windows, macOS, BSD, and embedded environments, and is built for maximum efficiency with minimal CPU and memory footprint. It exposes internal metrics over HTTP/Prometheus for monitoring.

Key Features

High performance with low memory footprint

Pluggable architecture with 70+ built-in plugins for Inputs, Filters, and Outputs

SQL Stream Processing for real-time analytics and transformation

Secure networking with built-in TLS/SSL support and async I/O

Monitoring via internal metrics exposed over HTTP/Prometheus

Extensibility: write plugins in C, filters in Lua, and outputs in Go

Supports logs, metrics, and traces with unified processing and delivery

Cross-platform support: Linux, Windows, macOS, BSD, and embedded environments

Pros & Cons

Pros

Lightweight and low resource usage suitable for constrained environments
CNCF graduated project with a mature and active open-source community
Supports multiple telemetry types (logs, metrics, traces) in a single agent
Wide platform compatibility including embedded systems
Rich plugin ecosystem for various input, filter, and output destinations

Cons

May require additional configuration and plugin development for custom data pipelines
Built-in monitoring is limited to HTTP/Prometheus endpoints; no built-in dashboards
Learning curve for advanced features like SQL stream processing and plugin development in C/Lua/Go

Best For

Centralized log collection and forwarding across cloud, on-premises, or edge environmentsMonitoring infrastructure metrics and application performance via real-time data pipelinesDistributed tracing collection and processing for observabilityStream processing and enrichment of telemetry data using SQL queriesEdge/IoT data collection with minimal resource consumption

FAQ

What is Fluent Bit?

Fluent Bit is a lightweight and high-performance Telemetry Agent designed to collect, process, and forward logs, metrics, and traces from any source to any destination. It is a CNCF graduated project.

Which platforms does Fluent Bit support?

Fluent Bit supports Linux, Windows, macOS, BSD, and embedded environments.

What types of data can Fluent Bit handle?

Fluent Bit can handle logs, metrics, and traces.

Is Fluent Bit a CNCF project?

Yes, Fluent Bit is a graduated CNCF Cloud Native Computing Foundation project, part of the Fluentd ecosystem.

Can I extend Fluent Bit with custom plugins?

Yes, Fluent Bit supports extensibility: you can write plugins in C, filters in Lua, and outputs in Go.