How did you measure the efficiency and quality of the service in your last project?

To measure the effectiveness and quality of the service in my last project, I used several key metrics:

• Response Time (Latency) — measured the average and peak request processing times to ensure the service responds quickly.
• Throughput — the number of requests processed per second.
• Error Rate — the percentage of failed requests or errors.
• Resource Load — CPU, memory, network usage.

For data collection, I used Prometheus with Grafana for visualization. I also conducted load testing using tools like k6 or Apache JMeter to test the service behavior under high load.

Here's an example of metrics code in Go using Prometheus:

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

var (
    requestDuration = prometheus.NewHistogramVec(
        prometheus.HistogramOpts{
            Name: "http_request_duration_seconds",
            Help: "Duration of HTTP requests.",
        },
        []string{"path"},
    )
)

func init() {
    prometheus.MustRegister(requestDuration)
}

func handler(w http.ResponseWriter, r *http.Request) {
    timer := prometheus.NewTimer(requestDuration.WithLabelValues(r.URL.Path))
    defer timer.ObserveDuration()

    // request processing
    w.Write([]byte("Hello, World!"))
}

func main() {
    http.HandleFunc("/", handler)
    http.Handle("/metrics", promhttp.Handler())
    http.ListenAndServe(":8080", nil)
}

Thus, I was able to monitor the performance and quality of the service in real-time and respond promptly to issues.