Enhancement

• #3961 in_tcp: Add send_keepalive_packet option
• #4025 buffer: backup broken file chunk
• #4027 Add warning messages for restoring buffer with flush_at_shutdown true
• #4028 Add logs for time period of restored buffer possibly broken

Bug Fix

• #3987 http_server_helper: Fix format of log messages originating from Async gem
• #4034 #4043 Change to not generate a sigdump file after receiving a SIGTERM signal on non-Windows
• #4030 out_forward: fix error of ack handling conflict on stopping with require_ack_response enabled
• #4064 #4065 #4086 #4090 #4096 Fix problem that some system configs are not reflected
• #4091 Fix bug that the logger outputs some initial log messages without applying some settings such as format
• #4054 Windows: Fix a bug that the wrong log file is reopened with log rotate setting when flushing or graceful reloading
• #4081 Fix race condition of out_secondary_file
• #4087 Suppress warning using different secondary for out_secondary_file
• #4066 Fix value of system_config.workers at run_configure.
  Change argument type of Fluent::Plugin::Base::configure() to Fluent::Config::Element only.
• #4092 Fix bug that Fluentd sometimes tries to use an unavailable port and fails to start on Windows

Misc

• #3899 Add method for testing filtered_with_time
• #4040 Replace $$ with Process.pid
• #4061 Relax required webric gem version
• #3968 #3996 #3997 CI fixes to support Ruby 3.2
• #3969 #3990 #4013 #4033 #4044 #4050 #4062 #4074 #4082 #4085 Other CI fixes
• #4026 #4069 Update MAINTAINERS.md

Contributors to this release (Alphabetical order)

• abetomo
• Daijiro Fukuda
• Fujimoto Seiji
• I326463
• Kentaro Hayashi
• Takuro Ashie
• Toru Takahashi