Filebeat: the lightweight shipper
Filebeat is a single Go binary (~30 MB) that tails log files, tracks offsets, and streams events upstream.
It supports modules for common log formats (nginx, apache, mysql, kubernetes) with ready-made parsers.
Resource overhead: typically 20–60 MB RAM, <1% CPU on a busy host. Safe to install on every production node.
No complex filter language — field extraction is handled either in Filebeat modules (ingest pipeline sent to Elasticsearch) or downstream in Logstash.