KNOWLEDGE BASE

Release Notes v5.0.3

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 v5.0.3.

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

For the new deferred ingress queue configuration and metrics introduced for HTTP-based inputs, see:

• What’s new in Fluent Bit v5.0: Shared HTTP listener settings
• Upgrade notes: Shared HTTP listener settings for HTTP-based inputs
• YAML Pipeline reference: Shared HTTP listener settings for inputs
• YAML Service reference: built-in HTTP server vs plugin http_server.* settings
• Monitoring: V2 metrics for fluentbit_input_http_server_ingress_queue_busy_total, fluentbit_input_http_server_ingress_queue_pending_bytes, and fluentbit_input_http_server_ingress_queue_pending_events
• HTTP input configuration
• Splunk input configuration
• Elasticsearch input configuration
• OpenTelemetry input configuration
• Prometheus remote write input configuration

What’s new ?

Core

• config: add extended environment variable support in YAML, including structured env entries with file-backed values and refresh intervals
• http_server: add ingress queue limit settings plus deferred ingress queue metrics for better backpressure visibility
• http_client: harden timeout handling, chunked response parsing, and connection teardown across shared HTTP paths
• tests: Fluent Bit now ships an in-tree integration test suite covering end-to-end scenarios across HTTP, OTLP, Kafka, S3, Syslog, Tail, and more
• network: handle bracketed IPv6 addresses correctly
• parser: fix timestamp parsing around DST changes just after local midnight
• cmetrics: upgrade to v2.1.2

Plugins

• eBPF (Input)
  • add TCP trace support and clean up eBPF programs more reliably on shutdown and exception paths
• OpenTelemetry (Input)
  • honor explicit tag configuration over URI-derived tags
• Tail (Input)
  • harden restart restore and aged-out file recovery to avoid resuming from stale offsets after copytruncate, inode reuse, or partial-line restarts
• Dummy (Input)
  • add support for dynamic environment values in body and metadata
• S3 (Output)
  • fix retry_limit semantics and multiple multipart upload memory-management issues
• Azure Logs Ingestion (Output)
  • validate auth_url overrides for safer OAuth2-based testing and setup
• Syslog (Output)
  • reject unsupported proto and TLS combinations more cleanly
• HTTP-based plugins
  • inputs and outputs using the shared HTTP client received timeout, chunked-response, and cleanup fixes across in_http, in_calyptia_fleet, filter_ecs, out_azure_blob, out_calyptia, out_http, out_opentelemetry, out_slack, out_td, and out_websocket

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: CNCF Slack, channel #fluent-bit (https://communityinviter.com/apps/cloud-native/cncf)
• Twitter: @fluentbit