Once you decide to centralize logs, you need actual tools to ship, parse, store and search them. ELK is a common open-source answer: Logstash parses, Elasticsearch stores and indexes, and Kibana lets you search, with Filebeat shipping logs from each server. Use it when you need fast full-text search across large volumes of logs. If cost matters more than full-text search, Grafana Loki indexes only labels and is cheaper to run.