Path: csiph.com!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!newsreader4.netcologne.de!news.netcologne.de!newsfeed.freenet.ag!news2.euro.net!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Newsgroups: comp.lang.python
Date: Sat, 13 Apr 2013 10:21:20 -0700 (PDT)
In-Reply-To: <mailman.540.1365805306.3114.python-list@python.org>
Complaints-To: groups-abuse@google.com
Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=213.238.76.128; posting-account=RvHFJQoAAABjGPM8XlLh6XgKam0WFBaf
References: <bf0b6bfd-9226-4bb4-9c77-3ec418a154a0@googlegroups.com> <mailman.540.1365805306.3114.python-list@python.org>
User-Agent: G2/1.0
MIME-Version: 1.0
Subject: Re: SimpleHTTPRequestHandler used with HTTP/1.1 hangs after the second resource on a page.
From: Piotr Dobrogost <p@google-groups-2013.dobrogost.net>
To: comp.lang.python@googlegroups.com
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: quoted-printable
Cc: python-list@python.org
Precedence: list
Message-ID: <mailman.560.1365874188.3114.python-list@python.org>
Lines: 61
NNTP-Posting-Host: 2001:888:2000:d::a6
Xref: csiph.com comp.lang.python:43531

On Saturday, April 13, 2013 12:21:33 AM UTC+2, Terry Jan Reedy wrote:
> I find the doc slightly confusing. The SO code uses BaseHTTPServer. The=
=20
> doc says "Usually, this module isn=92t used directly," On the other hand,=
=20
> SimpleHTTPServer only defines a request handler and not a server itself.

Thanks for taking time to reply.

Well, I've seen presentations where BaseHTTPServer is a recommended way of =
running simple, ad-hoc web server. In addition the documentation of http.se=
rver module in Python 3.3 (which contains implementation of the same HTTPSe=
rver class as found in BaseHTTPServer module in Python 2.x) does not contai=
n the statement you cited which I take to mean it can safely be used direct=
ly.

As Python 3.3.1 exhibits the same behavior let's focus on the following Pyt=
hon 3 version of the code from the original question:

from http.server import SimpleHTTPRequestHandler
from http.server import HTTPServer

class MyRequestHandler(SimpleHTTPRequestHandler):
    #protocol_version =3D "HTTP/1.0"   # works
    protocol_version =3D "HTTP/1.1"   # hangs

server =3D HTTPServer(("localhost", 7080), MyRequestHandler)
server.serve_forever()

> What does 'hang' mean? Does the page get displayed? If so,=20
> server.serve_forever is supposes to 'hang'.

I increased the number of resources to 7 to be able to detect possible patt=
erns. The page and some of the resources are being displayed almost instant=
ly. However browser waits for the requests to get remaining resources to fi=
nish and so those resources naturally are not being displayed. When browser=
 waits the code is stuck at the line I showed in my original post. What's i=
nteresting is that after some time the request to get the second resource (=
in case there are only 2 on the page) finishes. However the time spent wait=
ing for the second resource is ridiculously long compared to time spend wai=
ting for the first resource. For example in one of my tests Firebug showed =
waiting time for the first resource to be 4ms whereas the waiting time for =
the second resource to be 1m 55s.

> The SO post says
>=20
> class MyRequestHandler(SimpleHTTPRequestHandler):
>      #protocol_version =3D "HTTP/1.0"   # works
>      protocol_version =3D "HTTP/1.1"   # hangs
>=20
> so this should be some sort of clue. The code says
>=20
> 569 # The version of the HTTP protocol we support.
> 570 # Set this to HTTP/1.1 to enable automatic keepalive
> 571 protocol_version =3D "HTTP/1.0"

Sure, in version 1.1 of http the connection is not closed by default unless=
 'Connection: Close' header was sent in request. Firefox sends all requests=
 with 'Connection: keep-alive' header.

I don't really know how to debug this...