How are the methods of transmitting metrics by exporters implemented?

Methods of transmitting metrics by exporters are usually implemented through protocols and formats that allow collecting and transmitting monitoring data to aggregation systems (for example, Prometheus).

Main ways of transmitting metrics:

1. Pull model (polling) — the exporter provides an HTTP endpoint, which the monitoring system periodically queries to obtain current metrics in a format such as Prometheus exposition format.

2. Push model (sending) — the exporter itself sends metrics to the monitoring server via API or protocols (for example, Pushgateway in Prometheus).

3. Use of intermediate brokers — metrics are sent to a message queue (Kafka, RabbitMQ), from where the monitoring system retrieves them.

Example of exporting metrics in Prometheus (pull model):

import (
    "github.com/prometheus/client_golang/prometheus"
    "github.com/prometheus/client_golang/prometheus/promhttp"
    "net/http"
)

func main() {
    http.Handle("/metrics", promhttp.Handler())
    http.ListenAndServe(":2112", nil)
}

Here, the exporter runs an HTTP server that returns metrics in a format understandable by Prometheus.