// the find
fluent/fluentd
Fluentd: Unified Logging Layer (project under CNCF)
Fluentd is a long-standing, CNCF-hosted log collector/router written in Ruby, aggregating events from many sources and shipping them to files, databases, cloud services, and more via a plugin architecture. It's aimed at ops/infra engineers building log pipelines who want something more mature and plugin-rich than writing custom shippers.
The plugin ecosystem is genuinely huge (in_tail, forward, http, syslog inputs, dozens of output/formatter/parser plugins) and the plugin_helper abstractions (buffer, storage, service_discovery, retry_state) make writing new plugins straightforward without reinventing chunking/retry logic. Buffer chunk implementation (file and memory based) with configurable flush/retry semantics is solid and battle-tested at scale. It has an actual third-party security audit (Cure53) linked in the README, plus OpenSSF scorecard and CII badges, which is rare to see backed by real artifacts rather than just badges.
It's Ruby, so expect meaningfully higher memory/CPU overhead per node than Vector or Fluent Bit, which is why most people now pair Fluentd with Fluent Bit as the actual edge collector and use Fluentd only for aggregation. The plugin API and legacy v0.12 compat layers (visible in lib/fluent/compat/) add real complexity and cruft to the codebase you'll trip over if writing custom plugins. Configuration is its own DSL/format (plus a newer YAML parser bolted on) with a real learning curve, and debugging misbehaving buffer/retry state in production is not trivial from the docs alone.