v5.0.5

Next generation Telemetry Agent for Logs, Metrics and Traces.

May 7, 2026

KNOWLEDGE BASE

Release Notes v5.0.5

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 v5.0.5.

This maintenance release improves OTLP log grouping and routing correctness, adds new S3 and eBPF capabilities, and includes reliability improvements across AWS, Kubernetes, LogDNA, JSON handling, metrics, and build compatibility.

What’s new ?


Core


  • opentelemetry: improve OTLP log resource and scope preservation across ingestion, routing, and re-export
  • routing: enable conditional routing for threaded inputs and improve route preservation when records are split across matched and default routes
  • json: improve mutable JSON handling reliability for complex documents
  • aws: expand endpoint coverage for additional AWS region families
  • crypto: improve compatibility with OpenSSL builds without legacy engine support
  • tests: expand integration and runtime coverage for OTLP grouping, conditional routing, Forward metadata defaults, S3 OTLP JSON, LogDNA formatting, eBPF exec tracing, AWS regions, Kubernetes cleanup, and Log to Metrics timer retries

Libraries


  • cmetrics: upgrade the bundled library to v2.1.3 with improved OTLP metric compatibility and decoding reliability

Plugins


  • eBPF (Input)
    • add an exec trace for process execution observability
  • OpenTelemetry (Input)
    • improve OTLP log ingestion reliability and preserve scope metadata when converting logs into Fluent Bit events
  • S3 (Output)
    • add format otlp_json for writing log events to S3 as OTLP JSON, while keeping json_lines as the default format
    • improve validation for OTLP JSON output options
  • OpenTelemetry (Output)
    • improve grouped log reassembly while preserving resource and scope identity
    • improve metadata validation and OAuth2 cleanup during shutdown
  • Forward (Output)
    • retain metadata in forward mode by default through retain_metadata_in_forward_mode true
  • LogDNA (Output)
    • add exclude_promoted_keys to omit promoted meta, level or severity, app, and file fields from the line body while preserving non-promoted fields
  • Kubernetes (Filter)
    • improve token handling and AWS pod association resource cleanup
  • Log to Metrics (Filter)
    • improve timer-driven retry behavior for metrics emission
  • Node Exporter Metrics (Input)
    • handle unavailable IPv6 socket metrics cleanly

Contributors

On every release, there are many people involved doing contributions to different areas like bug reporting, troubleshooting, documentation and coding, without these contributions from the community, the project won’t be the same and won’t be in the good shape that it is now. So THANK YOU! to everyone who takes part of this journey!

Join us

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