సాధారణ నిరీక్షణ సాధనాలు ఏమిటి మరియు మీరు వాటి మధ్య ఎలా ఎంచుకుంటారు?

METRICS    Prometheus  → pull-based scraping, time-series DB, PromQL query language
           Grafana     → dashboards on top of Prometheus (and many other sources)

LOGS       ELK         → Elasticsearch + Logstash + Kibana (powerful, heavy to run)
           Loki        → "Prometheus for logs": cheap, indexes labels not full text

TRACES     Jaeger      → distributed tracing, OpenTelemetry-compatible
           Tempo       → trace backend that pairs with Grafana/Loki

ALL-IN-ONE Datadog     → managed metrics + logs + traces + APM in one product