Is there any way I can send large amounts of data (around 10,000 bytes) on UDP relatively fast using sockets?

Question

Is there any way to send large amounts of data (around 10,000 bytes) relatively fast? I'm currently using socket.recvfrom and it takes around a minute to recieve each message. Edit: This is how I recover the message, sock is a UDP socket, and max_buffer starts at 1024

 while True:
     try:
         data, addr = sock.recvfrom(max_buffer) # buffer 
         print(data)
         break
     except OSError:
         max_buffer *= 2
 data = json.loads(data)

Im not going to paste the code for getting the message because its pretty long, but its a json dictionary which in total takes up around 10000 bytes. This is how I send it:

sock.sendto(json.dumps(data).encode(), address)

I'm sending messages to the server repeatedly.

Over what media are you sending the packets? Ethernet? WiFi? Dial-up modem? How many hops between here and there? I'd expect that 10K bytes would go much more quickly than 1 second, let alone 1 minute. How are you measuring the time? — Robᵩ, Jun 19 '18 at 18:19
Post your code. There's no reason for it to take a minute to send 10KB. — John Kugelman, Jun 19 '18 at 18:54

Robᵩ · Accepted Answer · 2018-06-19T18:38:28.427

Is there any way to send large amounts of data (around 10,000 bytes) relatively fast?

Yes, use socket.sendto(). Here is an example client:

import socket
import datetime

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
data = bytes(i%256 for i in range(10000))
print(datetime.datetime.now())
s.sendto(data, ('localhost', 5000))
print(datetime.datetime.now())

Notice that it creates a bytes object of 10,000 bytes and passes it in a single call to s.sendto().

Using this server:

import socket
import datetime

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind(('localhost', 5000))
data, addr = s.recvfrom(100*1024)
print(datetime.datetime.now())

I got this result from the client:

2018-06-19 13:36:13.443418
2018-06-19 13:36:13.443636

I got this result from the server:

2018-06-19 13:36:13.443666

So to the sendto() call took about 2/10000 of a second and the data arrived less than 1/10000 of a second later.

You showed me the answer. I was starting max_buffer too low, so it was taking a long time for it to go up to a size in which it can recieve the packet. Thanks! — Gderu, Jun 19 '18 at 19:25
@Gderu - You might find this interesting: https://stackoverflow.com/a/2862176/8747 Especially, "*Use a buffer large enough to hold the biggest packet that your application-level protocol ever sends*". — Robᵩ, Jun 19 '18 at 19:43

Is there any way I can send large amounts of data (around 10,000 bytes) on UDP relatively fast using sockets?

1 Answers1