Python server program has high cpu usage
multithreading, python, tcp
Solution
You are using `setblocking(0)`, that means your socket is not blocking. What you are doing is called `polling` and will use as much CPU as it can.
When you use threading you don't need to poll. Just remove the `setblocking(0)` line and it should work properly.
Problem
I am experimenting with a python tcp server (I've just recently discovered the awesomeness that is python). Anyway, the server runs just fine and prints data the way I would expect, but when I look at the CPU usage in the windows task manager it shows that python.exe is consuming 97%-99% of the CPU. Just to see what would happen, I ran it again on a different computer and it only used about 50% of the cpu. Here is what I am wondering: Why is the cpu usage so high? Why would I see a difference running on two different machines (one is Windows 7 the other is server 2008, could that matter)? I am creating a new thread for each connnection, and running a while loop that is always true, but I have a "break" when there is no longer a connection. Is this thread getting destroyed correctly? Thanks in advance for any help! ``` import socket import threading import logging import time TCP_IP = "127.0.0.1" TCP_PORT = 10000 BUFFER_SIZE = 1024 SOCKET_TIMEOUT = 2 def handler(conn): while 1: try: data = conn.recv(BUFFER_SIZE) if data: dataS = data.decode(encoding = 'UTF-8') print ("received data: ") print (dataS) logging.getLogger("TestLogger").critical(dataS) except socket.error as e: print("connection closed") conn.close() break try: s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.bind((TCP_IP, TCP_PORT)) s.setblocking(0) s.listen(5) except Exception as e: print(e) while 1: try: conn, addr = s.accept() except Exception as e: continue print ('Connection address:') print (addr) conn.settimeout(SOCKET_TIMEOUT) connThread = threading.Thread(target = handler, args = (conn,)) connThread.start() ```