Performance issue when serving Python3.5 scripts through Apache + WSGI

[dandrei]

Windows build number: 10.0.16299.192

Hardware configuration:

Processor: Intel64 Family 6 Model 158 Stepping 9 GenuineIntel ~2808 Mhz
Total Physical Memory:     8,072 MB
SSD

Applications involved:

• apache2/xenial-updates,xenial-security,now 2.4.18-2ubuntu3.5 amd64
• python3/xenial,now 3.5.1-3 amd64
• libapache2-mod-wsgi-py3/xenial,now 4.3.0-1.1build1 amd64

What I'm doing:

• Serving a Python script from /var/www/html using Apache and WSGI
• Dependencies are installed inside a virtualenv

Relevant section from Apache's 000-default.conf site configuration:

WSGIDaemonProcess test_app user=www-data group=www-data processes=1 threads=5 python-home=/var/www/html/venv/lib/python3.5/site-packages/ request-timeout=1
WSGIScriptAlias / /var/www/html/wsgi.py

<Directory /var/www/html>
   WSGIProcessGroup test_app
   WSGIApplicationGroup %{GLOBAL}
   Require all granted
</Directory>

What's wrong:

• Even with request-timeout=1, processing still takes as long as 10 seconds.
• Without specifying request-timeout, processing hangs indefinitely.

What should be happening instead:

• Processing should be significantly faster, to aid in development.
• Identical configuration tested on a native Linux, there are no delays.

Hypothesis:

• The output is possibly generated, but fails to be delivered, that's why the timeout makes it work.

[therealkenc]

CONTRIBUTING.md. Probably #1671 et al given the nature of the pause, but who knows.