Prometheus

For the last decade, one answer has consistently risen above the noise: .

Prometheus is designed for reliability, not long-term storage. By default, data is stored locally on disk. If your server crashes, your historical data is gone. "Highly available" setups usually involve running two identical Prometheus servers (both scraping the same targets) and a separate Alertmanager to deduplicate alerts. This is wasteful and fragile. prometheus

In the sprawling, dynamic world of cloud-native computing, asking "Is the server up?" feels as archaic as asking for a fax number. The question has evolved into something far more complex: "How is my system behaving, where are its bottlenecks, and what will break next?" For the last decade, one answer has consistently

Prometheus is for metrics (numbers over time). It cannot replace logging (ELK Stack) or tracing (Jaeger). This is the "Three Pillars of Observability." If a user reports a slow checkout process, Prometheus can tell you latency spiked, but it cannot tell you which specific database query caused it. You need integration with other tools. If your server crashes, your historical data is gone