Fluentd & Fluent Bit

The production grade telemetry ecosystem

Telemetry data processing can be complex, especially at scale. That's why Fluentd was created. Fluentd is more than a simple tool, it's grown into a fullscale ecosystem that contains SDKs for different languages and subprojects like Fluent Bit.

Here, we describe the relationship between the Fluentd and Fluent Bit open source projects.

Both projects are:

• Licensed under the terms of Apache License v2.0.

• Graduated hosted projects by the Cloud Native Computing Foundation (CNCF).

• Production grade solutions: Deployed millions of times every single day.

• Vendor neutral and community driven.

• Widely adopted by the industry: Trusted by major companies like AWS, Microsoft, Google Cloud, and hundreds of others.

The projects have many similarities: Fluent Bit is designed and built on top of the best ideas of Fluentd architecture and general design. Which one you choose depends on your end-users' needs.

The following table describes a comparison of different areas of the projects:

Attribute	Fluentd	Fluent Bit
Scope	Containers / Servers	Embedded Linux / Containers / Servers
Language	C & Ruby	C
Memory	Greater than 60 MB	Approximately 1 MB
Performance	Medium Performance	High Performance
Dependencies	Built as a Ruby Gem, depends on other gems.	Zero dependencies, unless required by a plugin.
Plugins	Over 1,000 external plugins available.	Over 100 built-in plugins available.
License	Apache License v2.0	Apache License v2.0

Both Fluentd and Fluent Bit can work as Aggregators or Forwarders, and can complement each other or be used as standalone solutions.

In the recent years, cloud providers have switched from Fluentd to Fluent Bit for performance and compatibility. Fluent Bit is now considered the next-generation solution.