v5.1.4

KNOWLEDGE BASE

Release Notes v5.1.4

Fluent Bit is a Fast and Lightweight Telemetry Agent for Linux, BSD, macOS and Windows. We are proud to announce the availability of Fluent Bit v5.1.4.

For people upgrading from previous versions, please read the Upgrading Notes section of our documentation:

https://docs.fluentbit.io/manual/5.1/installation/upgrade_notes

Fluent Bit v5.1.4 is a maintenance release that improves ingestion resilience, metadata preservation, multiline processing, and GELF delivery. It also corrects stream processor query behavior and improves compatibility with older build environments.

The release contains 53 commits since v5.1.3, with improvements across the engine, networking, inputs, filters, outputs, bundled libraries, packaging, and test coverage.

For users upgrading from earlier releases, v5.1.4 also includes the 5.1 series’ expanded output formats: Kafka Avro and optional Protobuf serialization with Schema Registry integration, Arrow and Parquet output for Amazon S3, and Parquet compression options for Google Cloud Storage.

What’s new ?

Core

• compression: improve resource control and validation when processing compressed payloads
• HTTP client: improve request validation for reliable outbound communication
• encoding: reject empty JSON documents consistently
• lifecycle: improve output cleanup during shutdown
• multiline: consistently honor multiline_buffer_limit for CRI and Docker logs, preserve metadata when truncating messages, and improve flush error handling
• stream processor: correct logical operator precedence in SQL conditions so NOT, AND, and OR produce the expected query results
• packaging: use archived Debian Bullseye repositories to keep builds working and verify public release metadata and download availability during release publication
• tests: expand coverage for ingestion limits, compressed payloads, metadata preservation, multiline truncation, GELF delivery, query conditions, and hot reload with glob includes

Libraries

• cfl: upgrade to v1.0.2, improving time API portability
• flb_libco: refresh the bundled coroutine library, improving AArch64 compatibility and runtime coverage
• zstd: allow the bundled library to build with only a C compiler
• Ripser: improve compatibility with older GCC toolchains

Plugins

Inputs

• Forward
  • improve resource control during MessagePack ingestion and add msgpack_memory_limit to configure the decoding memory budget
• OpenTelemetry
  • enforce ingestion size limits consistently for compressed gRPC requests

Processors & Filters

• Kubernetes
  • improve pod and namespace validation and handling of empty or malformed records
• Rewrite Tag
  • preserve group metadata and resource attributes when records are routed to new tags or retained under their original tags

Outputs

• GELF
  • recover UDP delivery after send failures and improve concurrent worker handling
  • handle oversized records consistently so other records can continue to be delivered

Join us

We want to hear from you. Our community keeps growing, and you can be part of it:

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