Where should you turn if the server is running slowly?

1. System Monitoring:

   • Check CPU load, memory usage, disk input/output.
   • Use tools like Prometheus, Grafana, top, htop.

2. Application logs:

   • Study logs for errors, warnings, stack traces.
   • Pay attention to long queries, locks.

3. Code profiling:

   • Use the standard pprof package for performance analysis.
   • Look for "bottlenecks" - functions consuming a lot of CPU or memory.

// Example of using pprof
import (
	"log"
	"net/http"
	_ "net/http/pprof" // Register pprof handlers
)

func main() {
	go func() {
		log.Println(http.ListenAndServe("localhost:6060", nil))
	}()
	// Your main application code
}

• Visualize profiling results using Graphviz or built-in go tool pprof tools.

4. Database connections:

   • Check slow queries.
   • Optimize SQL queries, add indexes.
   • Ensure connection pool adequacy.

5. Network:

   • Check delays and packet loss between client and server, as well as between system components (e.g., services, database).

6. Third-party services:

   • If the application interacts with external APIs, check their responsiveness.

7. Configuration:

   • Check OS settings, Go runtime (e.g., GOMAXPROCS), web server (Nginx, Caddy).

8. Concurrency and parallelism:

   • Analyze goroutine and channel usage, look for deadlocks or excessive goroutine creation.

9. GC (garbage collector):

   • Monitor GC activity.
   • A high number of allocations or long GC pauses may indicate memory issues.

10. Deployment and infrastructure:

    • Check host, container, virtual machine status.
    • Ensure sufficient resources.