軽量なデータ転送を実現するBeats

Logstash is powerful but heavy. To collect data right at the source (a server, container, or device) Elastic offers Beats: small, single-purpose agents written in Go that ship data efficiently.

Each Beat focuses on one job and runs as a tiny resident process with a low memory footprint, making it safe to deploy on thousands of machines simultaneously.

Filebeat tails log files and forwards each line. It tracks read offsets so it resumes correctly after a restart and never loses or duplicates lines under normal operation.

Metricbeat collects system and service metrics: CPU, memory, disk, plus modules for databases, web servers, and more. It samples on an interval and ships structured metric events.

The family includes Packetbeat (network traffic), Heartbeat (uptime monitoring), Auditbeat (audit data), and Winlogbeat (Windows event logs). You pick the Beat that matches your data.

Beats can ship directly to Elasticsearch for simple pipelines, or to Logstash when you need heavy parsing and enrichment before storage.

Beats modules come with prebuilt parsing, index templates, and Kibana dashboards. Enabling the nginx module instantly gives you parsed access logs and ready-made visualizations.

When shipping straight to Elasticsearch, Beats can invoke ingest pipelines on the cluster to parse and transform data, replacing much of Logstash for simpler cases.

If the output is slow or down, Beats apply back-pressure and slow their reads rather than dropping data. Filebeat keeps its position in the file until delivery is acknowledged.

A common architecture uses Beats at the edge for collection and Logstash centrally for transformation: Beats collect, Logstash processes, Elasticsearch stores. Use Beats alone when no heavy parsing is needed.

The newer Elastic Agent unifies multiple Beats into a single managed agent controlled by Fleet, simplifying large deployments. The underlying Beats concepts still apply.

Test your understanding of Beats.

You learned about lightweight data shippers:

• Beats are small Go agents, each focused on one data type.
• Filebeat ships logs; Metricbeat ships metrics; others cover network, uptime, and Windows events.
• Beats output to Elasticsearch or Logstash and ship prebuilt modules and dashboards.
• They apply back-pressure to avoid data loss, and Elastic Agent unifies them under Fleet.