How to diagnose a memory leak in a service? What actions should be taken?

To diagnose a memory leak in a service, you need to:

1. Collect memory usage metrics — monitoring through tools (e.g., Prometheus, Grafana).
2. Create a memory dump (heap dump) — using profilers (e.g., VisualVM, pprof for Go).
3. Analyze the dump — look for objects that are not released and accumulate over time.
4. Check the code for cyclic references or improper resource management.
5. Fix the identified issues — for example, remove unnecessary references, optimize caches.
6. Retest — ensure that the leak is resolved.

Example for Go using pprof:

import (
    "net/http"
    _ "net/http/pprof"
)

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

Then you can connect to http://localhost:6060/debug/pprof/ and collect a memory profile for analysis.