Fluentd Blog

fluent-package v6.1.0 has been released

Hi users!

We have released fluent-package v6.1.0 on 2026-10-29. Fluent Package is a stable distribution package of Fluentd. (successor of td-agent)

This is a new release of the v6.1 series. Note that this is NOT an LTS version. If you prefer stability, please use the LTS version (v6.0.x) instead.

Fluent Package v6.1.0

Fluent Package v6.1.0 includes the following improvements:

• Updated bundled Fluentd to v1.20.0.
• Updated bundled Ruby to 3.4.11 (same as v6.0.5 LTS)
• Updated most of bundled gems
• Changed to keep compatibility with older RHEL 9.x/10.x (#1087, #1088)
• msi: fix broken link to enterprise services (#1078)
• Drop LTO flags on RHEL 10.x and Ubuntu. Note that hardening flags are kept. (#1101)
• ARM64 windows has been supported (#1132)

This article explains the changes in Fluent Package v6.1.0.

Changes

Updated bundled Fluentd to v1.20.0.

Unlike v1.19.x, which is bundled in the LTS version, Fluentd v1.20.0 includes not only many bug fixes but also includes new major features.

See the following Fluentd v1.20.0 has been released article in details.

If you want to use the latest features right away, we recommend this version. If you prefer stability, please keep using the LTS version.

Updated bundled Ruby to 3.4.11

Ruby 3.4.11 is a maintenance release. Compared to Ruby 3.4.5 which was bundled in the previous version (v6.0.0), it includes the following security fixes in bundled gems:

• uri: CVE-2025-61594 (fixed in Ruby 3.4.7)
• rexml: CVE-2025-58767 (fixed in Ruby 3.4.8)
• zlib: CVE-2025-58767 (fixed in Ruby 3.4.9)
• net-imap: CVE-2026-47240, CVE-2026-47241, CVE-2026-47242 (fixed in Ruby 3.4.10)
• resolv: CVE-2026-80212 and CVE-2026-80213 (fixed in Ruby 3.4.11)

For details, please see the Ruby 3.4.7, Ruby 3.4.8, Ruby 3.4.9, Ruby 3.4.10 and Ruby 3.4.11 release notes.

ARM64 windows has been supported

Even though Windows arm64 hosted runners were available, fluent-package didn't support it for a long time.

We decided to include Windows ARM64 support to prepare for the upcoming v7 release.

As a side effect, nokogiri is no longer bundled on Windows, including x86_64.

There are some bundled fluentd plugins which use it, but they have been updated to use alternatives such as REXML.

msi: fixed a broken link to enterprise services on popup window

The link to the enterprise services page on the popup window of the Windows installer was broken. It has been fixed in this release. (#1079)

rpm: keep compatibility with older RHEL 9.x and 10.x

The packages for RHEL 9.x and 10.x were built on the latest minor version of each series. As a result, the built binaries required newer symbols such as GLIBC_2.35 or OPENSSL_3.4.0, and they did not work on older minor versions like RHEL 9.6 or RHEL 10.1.

To keep the ABI compatible in the whole 9.x and 10.x series, the build environment is now pinned to RHEL 9.2 and RHEL 10.0. (#1089, #1090)

This issue was fixed and shipped as 6.0.4-2 on above platforms which had been implemented in advance, has now been officially released.

rpm deb: disable LTO for RHEL 10 and Ubuntu

RPM 4.19 (AlmaLinux 10) and dpkg-buildflags on Ubuntu export LTO (Link Time Optimization) flags (-flto=auto -ffat-lto-objects) into the build process. These flags leaked into jemalloc, Ruby and native gem extensions, and made the build much slower. For example, the total build time on AlmaLinux 10 grew extraordinaly.

Since the bundled Ruby uses its own optimization settings, LTO gives no measurable benefit here. So we removed the LTO flags and the annobin plugin from the build environment. The hardening flags such as stack protection, control flow protection and FORTIFY_SOURCE are kept as before.

This change also means that native extensions which users build with fluent-gem install no longer inherit the LTO overhead. (#1102)

Download

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