v4.2.2

KNOWLEDGE BASE

Release Notes v4.2.2

Fluent Bit is a Fast and Lightweight Data Processor and Forwarder for Linux, BSD, Windows and macOS. We are proud to announce the availability of Fluent Bit v4.2.2.

Below is a detailed list of changes included in this release…

What’s new ?

Fluent Bit v4.2.2 is a maintenance release featuring improved IPv6 address support, AWS simple_aggregation operation for Kinesis Firehose and Kinesis Streams, increased CloudWatch Logs event length limit to 1MB, and multiple library upgrades including SQLite, c-ares, monkey, cmetrics, and LuaJIT. This is the final release of 2025, happy holidays :) .

Core

• http_client: add ipv6 bracket if missing from host address (PR #11181)
• network: Add ws2tcpip.h to avoid missing func defs (PR #11181)
• utils: fix support for ipv6 addresses (PR #11181)t/fluent-bit/pull/11258))
• aws
  • Implement simple_aggregation operation (PR #11284)
  • utils: set up HTTP debug plumbing for AWS HTTP clients (PR #11015)

Libraries

• sqlite: upgrade to v3.51.1 (PR #11309)
• c-ares: upgrade to v1.34.6 (PR #11309)
• monkey: upgrade to v1.8.6 (PR #11309)
• cmetrics: upgrade to v1.0.6 (PR #11309)
• luajit: upgrade to 7152e154 (20251223) (PR #11309)

Plugins

• Cloudwatch_logs (Output)
  • increase MAX_EVENT_LEN to 1MB with tests (PR #11159)
• Kinesis_firehose (Output)
  • Add simple_aggregation operation (PR #11284)
  • enable HTTP debugging for AWS client requests (PR #11015)
• Kinesis_streams (Output)
  • Add simple_aggregation operation (PR #11284)

Join us

We want to hear about you, our community is growing, and you can be part of it!, you can contact us at:

• Github: http://github.com/fluent/fluent-bit
• Slack: http://slack.fluentd.org
• Twitter: @fluentbit