Tell me about setting up monitoring: Prometheus servers, Grafana, agents, logging.

Monitoring setup using Prometheus and Grafana typically includes the following components:

• Prometheus server — collects metrics from various sources, stores them, and provides an API for queries.
• Exporters (agents) — specialized programs or libraries that gather metrics from applications, OS, databases, and transmit them to Prometheus. For example, node_exporter for OS metrics, blackbox_exporter for service availability checks.
• Grafana — visualization tool that connects to Prometheus and builds dashboards based on metrics.
• Logging — complements monitoring, helps analyze events and errors. Usually, a centralized stack (e.g., ELK: Elasticsearch, Logstash, Kibana) or Loki from Grafana is used.

Example setup:

1. Install Prometheus and configure the prometheus.yml file with target (exporter) addresses.
2. Run necessary exporters on servers or in containers.
3. Install Grafana, add Prometheus as a data source.
4. Create dashboards for monitoring key metrics (CPU load, memory, delays, errors).
5. Configure alerts in Prometheus or Grafana for notifications on anomalies.

Thus, monitoring ensures collection, storage, visualization, and alerting on metrics and logs, which helps quickly respond to infrastructure issues.