Graylog Open — #5 Alternative to Splunk
Centralized syslog, GELF, and pipeline log management server with fast alert streams
Graylog Open provides structured GELF ingestion, Grok/pipeline log parsing, role-based views, and correlation alerts over OpenSearch and MongoDB without arbitrary daily GB license lockouts.
License: SSPL-1.0 · Pricing: Open Core · Compare all Splunk alternatives · Official Website