Python3 requests.get is too slow

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EDIT Adding info:

requests version: 2.21.0

Server info: a Windows python implementation which includes 10 instances of threading.Thread, each creating HTTPServer with a handler based on BaseHTTPRequestHandler. My do_GET looks like this:

def do_GET(self):
    rc = 'some response'
    self.send_response(200)
    self.send_header('Content-type', 'text/html')
    self.send_header('Access-Control-Allow-Origin', '*')
    self.end_headers()
    self.wfile.write(rc.encode('utf-8'))

I'm getting a strange behaviour.

Using the curl command line, the GET command is finished quickly:

curl "http://localhost:3020/pbio/button2?cmd=uz-crosslink-leds&g1=0&g2=0&g3=0&g4=1&tmr=1"

However, using requests.get() of python takes too much time. I was isolated it up to

python -c "import requests; requests.get('http://localhost:3020/pbio/button2?cmd=uz-crosslink-leds&g1=0&g2=0&g3=0&g4=1&tmr=1')"

I scanned through many other questions here and have tried many things, without success.

Here are some of my findings:

  • If I'm adding timeout=0.2, the call is ending quickly without any error.
  • However, adding timeout=5 or timeout=(5,5)` doesn't make it take longer. It always seem to be waiting a full one second before returning with results.
  • Working with a session wrapper, and cancelling keep-alive, didn't improve. I mean for this:
with requests.Session() as session:
    session.headers.update({'Connection': 'close'})
    url = "http://localhost:3020/pbio/button2?cmd=uz-crosslink-leds&g1=0&g2=0&g3=0&g4=%d&tmr=0" % i
    session.get(url, timeout=2)
  • Enabling full debug, I'm getting the following output:
url=http://localhost:3020/pbio/button2?cmd=uz-crosslink-leds&g1=0&g2=0&g3=0&g4=1&tmr=0
DEBUG:urllib3.connectionpool:Starting new HTTP connection (1): localhost:3020
send: b'GET /pbio/button2?cmd=uz-crosslink-leds&g1=0&g2=0&g3=0&g4=1&tmr=0 HTTP/1.1\r\nHost: localhost:3020\r\nUser-Agent: python-requests/2.21.0\r\nAccept-Encoding: gzip, deflate\r\nAccept: */*\r\nConnection: close\r\n\r\n'
reply: 'HTTP/1.0 200 OK\r\n'
header: Server: BaseHTTP/0.6 Python/3.7.2
header: Date: Wed, 01 May 2019 15:28:29 GMT
header: Content-type: text/html
header: Access-Control-Allow-Origin: *
DEBUG:urllib3.connectionpool:http://localhost:3020 "GET /pbio/button2?cmd=uz-crosslink-leds&g1=0&g2=0&g3=0&g4=1&tmr=0 HTTP/1.1" 200 None
url=http://localhost:3020/pbio/powermtr?cmd=read-power-density
DEBUG:urllib3.connectionpool:Resetting dropped connection: localhost
slight pause here
send: b'GET /pbio/powermtr?cmd=read-power-density HTTP/1.1\r\nHost: localhost:3020\r\nUser-Agent: python-requests/2.21.0\r\nAccept-Encoding: gzip, deflate\r\nAccept: */*\r\nConnection: close\r\n\r\n'
reply: 'HTTP/1.0 200 OK\r\n'
header: Server: BaseHTTP/0.6 Python/3.7.2
header: Date: Wed, 01 May 2019 15:28:30 GMT
header: Content-type: text/html
header: Access-Control-Allow-Origin: *
DEBUG:urllib3.connectionpool:http://localhost:3020 "GET /pbio/powermtr?cmd=read-power-density HTTP/1.1" 200 None
6.710,i=4
url=http://localhost:3020/pbio/button2?cmd=uz-crosslink-leds&g1=0&g2=0&g3=0&g4=4&tmr=0
DEBUG:urllib3.connectionpool:Resetting dropped connection: localhost
slight pause here
...

1 Answers

-1
Lucas Kaniak On

From the docs:

timeout is not a time limit on the entire response download; rather, an exception is raised if the server has not issued a response for timeout seconds (more precisely, if no bytes have been received on the underlying socket for timeout seconds). If no timeout is specified explicitly, requests do not time out.