Monitoring Ports: Prometheus (9090), Grafana (3000), Elasticsearch (9200)

Monitoring and Observability Ports

Modern infrastructure observability relies on a stack of tools for metrics, logs, and visualization.

Prometheus Stack

Port	Service
9090	Prometheus server (Web UI + API)
9091	Prometheus Pushgateway
9093	Alertmanager
9100	Node Exporter (system metrics)
9104	MySQL Exporter
9187	PostgreSQL Exporter
9216	MongoDB Exporter

Prometheus scrapes metrics from these exporters at configured intervals. The exporter ports follow the convention of 9xxx.

ELK / Elasticsearch Stack

Port	Service
9200	Elasticsearch HTTP API
9300	Elasticsearch transport (node-to-node)
5601	Kibana web interface
5044	Logstash Beats input
9600	Logstash monitoring API

Visualization

Port	Service
3000	Grafana dashboard
8086	InfluxDB HTTP API
4317	OpenTelemetry gRPC collector
4318	OpenTelemetry HTTP collector

Security Considerations

Monitoring tools often expose sensitive infrastructure data. Protect these ports:

1. Never expose monitoring ports to the public internet
2. Use reverse proxies with authentication for Grafana and Kibana
3. Enable Elasticsearch security features (X-Pack) for authentication
4. Restrict Prometheus scrape targets with firewall rules
5. Use mTLS for OpenTelemetry collectors

# Nginx reverse proxy for Grafana with auth
server {
    listen 443 ssl;
    server_name grafana.internal.example.com;
    location / {
        proxy_pass http://localhost:3000;
        auth_basic "Restricted";
    }
}