Fluentd Unified Logging Collector

A Cloud Native Computing Foundation graduated project under the Apache 2.0 license, providing an open-source unified logging layer that decouples data sources from backend systems through a pluggable architecture. Written in Ruby, the project has earned praise from Yukihiro Matsumoto, the creator of Ruby, for achieving programmer happiness and performance simultaneously, and from Heroku co-founder Adam Wiggins for championing the concept that logs are streams rather than files. Over 5,000 data-driven companies rely on the platform including Amazon Web Services, Microsoft, Atlassian, Nintendo, Twilio, and Tencent, with the largest known user collecting logs from over 50,000 servers through a single deployment. The core maintains simplicity through a minimal processing engine while 500-plus community plugins connect to diverse data sources including application logs, system journals, network protocols, cloud platform APIs, container runtimes, and message queues, and to equally diverse outputs including Elasticsearch, Amazon S3, MongoDB, Kafka, Datadog, Splunk, and standard HTTP endpoints. Event routing uses tag-based matching with pattern rules that selectively direct records to multiple outputs, while buffering provides in-memory and file-based persistence with configurable flush intervals, chunk sizes, and retry strategies for reliable delivery under backpressure. The lightweight sibling project Fluent Bit extends the same architecture to edge and embedded environments with a C implementation consuming under 450 kilobytes of memory.