Vector

Vector is completely free and open source, originally created by Timber and now maintained by Datadog. You can run it without any licensing costs.

Vector is a high-performance observability data pipeline written in Rust. It collects, transforms, and routes logs, metrics, and traces from your infrastructure with excellent performance.

Vector is significantly faster due to its Rust implementation and handles high throughput better. Fluentd is more mature with a larger plugin ecosystem. Choose Vector when performance matters.