How to set up centralized logging?

· Category: DevOps & CI/CD

Short answer

Centralized logging collects logs from all systems into a single platform for searching, analysis, and alerting. Common stacks include ELK, Fluentd, and Grafana Loki.

Steps

  1. Deploy log collectors on each node.
  2. Forward logs to a central aggregator.
  3. Store and index logs.
  4. Search and visualize with a UI.

Example

fluentd:
  sources:
    - type: tail
      path: /var/log/app.log
      tag: app
  matches:
    - tag: app
      type: elasticsearch
      host: elasticsearch

Tips

  • Use structured logging for easier parsing.
  • Set retention policies to manage costs.
  • Secure log transport with TLS.

Common issues

  • Log volume can overwhelm storage.
  • Parsing unstructured logs is error-prone.
  • Time synchronization is critical.