Fluent Bit

Fluent Bit is a high-performance, lightweight log processor and forwarder that has become the industry standard for cloud-native observability pipelines. With a footprint of approximately 450KB, it is designed to collect, parse, filter, and route logs, metrics, and traces from various sources to multiple destinations with minimal resource consumption. As a graduated project of the Cloud Native Computing Foundation (CNCF), it has been deployed over fifteen billion times worldwide and processes more than one petabyte of telemetry data daily from over one billion sources. The latest stable release, version 5.0.8, features native OpenTelemetry Protocol (OTLP) support for ingestion and delivery, enabling modern telemetry pipelines that span logs, metrics, and traces in a single lightweight binary. Fluent Bit offers over 100 built-in plugins for input sources including tail files, systemd, Docker, Kubernetes node logs, MQTT, and HTTP endpoints, as well as output destinations ranging from Elasticsearch, Kafka, Splunk, Datadog, and New Relic to cloud services like Amazon S3, Google Cloud Logging, and Azure Log Analytics. It supports advanced data processing capabilities including Lua scripting for custom transformations, sampling and filtering rules, record modification, and multi-destination routing with content-based conditional logic. The tool is widely adopted by major technology companies including Google, Microsoft, Amazon Web Services, Cisco, Datadog, Splunk, Walmart, LinkedIn, VMware, Dell, General Motors, and Lyft. Fluent Bit excels in containerized and edge computing environments where resource efficiency is critical, and its C-based architecture ensures sub-millisecond processing latency even under heavy load.