New Chapter of Fluentd, Rebranding and New Release Cycle (LTS)

### Overview In this talk, Fluentd maintainers and Clear Code software engineers Daiko Roppa and Kentaro Hayashi discuss the transition of the Fluentd distribution package from TD Agent to "fluent-package," alongside the introduction of a new Long-Term Support (LTS) release cycle. Fluentd—originally started in 2011 at Treasure Data and now a graduated project under the Cloud Native Computing Foundation (CNCF)—acts as an open-source data collector that unifies data collection and consumption across diverse inputs and outputs. The speakers outline why rebranding was necessary, how the new release channels operate, the technical challenges in upgrading, and the community's future roadmap.

### Key Topics - **Origins and Rebranding**: Historically, Treasure Data packaged Fluentd as "TD Agent" (bundled with Ruby and popular plugins). Because development shifted to a broader community model and TD Agent is no longer limited to Treasure Data's services, it has been rebranded to "fluent-package" to clearly communicate that it delivers Fluentd. - **LTS vs. Standard Release Cycles**: Fluent-package introduces two channels. The Standard channel updates minor versions approximately every three months for users wanting immediate access to new features. The LTS channel (starting with version 5.0.2 released in November) runs for roughly two years, receiving strictly bug fixes and security patches to ensure stability and compatibility in production environments before the planned version 6 release in 2025. - **End of Life for TD Agent v4**: TD Agent version 4 reaches its end of life (EOL) at the end of 2023, necessitating migration to fluent-package.

### Technical Details - **Migration and Compatibility**: The maintainers built transitional support to preserve backwards compatibility when upgrading from TD Agent v4. Existing command names, configuration files, and usernames/groups remain functional via symlinks, aliases, and internal transition logic. However, clean/new installations do not provide this legacy compatibility layer. - **Platform-Specific Considerations**: - *General*: Locally installed Ruby gems under TD Agent paths are not automatically recognized; users must reinstall them for fluent-package (assisted by the `fluent-diagtool` gem). - *Linux*: File paths for configuration, log files, and systemd service units change to Fluentd names, requiring updates if customized. - *Windows*: Command-line arguments must be reconfigured because fluent-package resets them. Additionally, fluentd service does not automatically start by default on Windows to allow configuration beforehand. The speakers recommend using the `system` directive introduced in TD Agent 4.4.2 to handle log rotation directly within configuration files instead of command-line flags. - **Core Improvements**: Fluent-package bundles Ruby 3.2 (replacing EOL Ruby 2.7), which offers better performance and enables testing experimental features like YJIT. Additionally, a longstanding, elusive bug in `in_tail` (which occasionally stopped tailing appended log contents) was resolved in Fluentd 1.16.2 and 1.16.3 with community assistance.

### Takeaways Repository telemetry shows significant traffic still requesting deprecated versions (v3 and v2), with high usage across the US, Netherlands, Japan, France, and Iraq, as well as an increase in ARM architecture adoption. The maintainers strongly urge users to migrate from legacy TD Agent releases to fluent-package LTS. In the Q&A, the speakers clarify that Fluentd is not being deprecated in favor of Fluent Bit; both will coexist, with Fluent Bit serving lightweight forwarding roles and Fluentd acting as a flexible, Ruby-extensible aggregator.