Proxy.pac problem

Fabio
Fabio used Ask the Experts™
on
Hello friends,

I have been successfully using proxy.pac on my network for a long time, but recently I have noticed a problem that is getting worse (and I'm not finding a solution)...

Within minutes most computers are making hundreds (sometimes thousands) of requests to the webserver (apache) to load proxy.pac.

Analyzing Apache logs and network traffic, proxy.pac is successfully transferred on all requests.

As result of this: apache logs increase dramatically in a short time, network traffic (between stations and web server with proxy.pac) also increases tremendously and there is a considerable loss of speed / performance to open Internet pages.

This issue happens regardless of operating system (Windows or Mac OS X). The default browser used on the network is Google Chrome.

Has anyone here ever been through this? Tips?

Thank you in advance.
Comment
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
David FavorLinux/LXD/WordPress/Hosting Savant
Distinguished Expert 2018

Commented:
Will likely be useful to attach a copy of an Apache log + whatever log file shows how proxy.pac is making choices about server connections.

If you're command line savvy, install XCode + MacPorts + tshark, then study traffic between your machine + Apache.

Also describe why you're using proxy.pac, so exact problem proxy.pac solves for you.

Note: Also run without proxy.pac to see if problem clears up.
Distinguished Expert 2018

Commented:
We need more information... how is the network set up? When should systems need to get the proxy.pac file? And do you have an idea of which systems are fetching it?
Software Engineer
Distinguished Expert 2018
Commented:
Did you setup the HTTP headers to allow proxy.pac to be cached for some amount of time.
(1 hour, 3600 seconds should be resonable..).

Be sure there are no errors in the .PAC file.

Here is a site dedicated to proxy.pac ... etc. https://findproxyforurl.com/common-pac-issues/
FabioConsultant

Author

Commented:
Hello guys!

First of all, thanks for your attention and help!

I am collecting the information you requested and soon post it here! So, with more information, I think it makes it easier for you to help me solve this problem.

In the meantime, I'm trying noci's suggestion option about HTTP headers and object expiration / caching (in this case proxy.pac)...

Again... thanks indeed for your time, attention and patience! :D

Best Regards!
FabioConsultant

Author

Commented:
Hey guys,

Thanks indeed for all your suggestions, tips and observations!!!

I just found the problem ... and please don't laugh (much) ... it was a typo in the proxy.pac itself... on one of the lines, instead of commenting with "//" I ended up commenting with "#"... :(

I found the error after noci advise to check if there were no errors in proxy.pac.

I use Linux (Debian) and used "pactester" to check the proxy.pac file.

this is the link (step by step) to how to install pactester: https://www.cyberciti.biz/faq/linux-unix-appleosx-bsd-test-proxy-pac-file-syntax/

Thanks again for your help ... If I can help you with anything, when you need it, you can contact me anytime.

Best Regards,
Fabio

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial