server_threaded_ProcessPool.py

# server.py
# Fib microservice (original showed by @dabaez ... I get NO credits!)

from socket import socket, AF_INET, SOCK_STREAM, SOL_SOCKET, SO_REUSEADDR
from fib import fib
from threading import Thread
from concurrent.futures import ProcessPoolExecutor as Pool

pool = Pool(4)

def fib_server(address):
  sock = socket(AF_INET, SOCK_STREAM)
  sock.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
  sock.bind(address)
  sock.listen(5)
  while True:
    client, addr = sock.accept()
    print("Connection", addr)
    Thread(target=fib_handler, args=(client,)).start()

def fib_handler(client):
  while True:
    req = client.recv(100)
    if not req:
      break
    n = int(req)
    future = pool.submit(fib, n)
    result = future.result()
    resp = str(result).encode('ascii') + b'\n'
    client.send(resp)
  print("Closed")

fib_server(('',25000))