Issue 343856 in chromium: Chrome Broswser - WPAD file is always getting downloaded from the server instead of cache

[chro...@googlecode.com]

Status: Unconfirmed
Owner: ----
Labels: Type-Bug Pri-2 Cr-Enterprise

New issue 343856 by radiaraj...@gmail.com: Chrome Broswser - WPAD file is
always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Google Chrome for Business v29.

Hi Team,

We are using Google Chrome for Business v29 in Enterprise corporate
environment. The issue is Google Chrome is always downloading WPAD.DAT from
the server instead of taking from the local pc cache. Could you advise.

Regards,
S. Rajini

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Updates:
Labels: Cr-Internals-Network-Proxy

Comment #1 on issue 343856 by joaod...@chromium.org: Chrome Broswser -

WPAD file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

(No comment was entered for this change.)

[chro...@googlecode.com]

Comment #2 on issue 343856 by radiaraj...@gmail.com: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Team,

Could you assist,

since Chrome is sending too many request to server to downloa wpad file.
Thanks.

[chro...@googlecode.com]

Comment #3 on issue 343856 by mme...@chromium.org: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Could you be clearer what the issue is? Is Chrome downloading WPAD every
time it's started, or is it downloading it multiple times without being
restarted?

For the former, I don't believe we don't put WPAD in the cache (And given
that WPAD may change between networks, that's probably the behavior we
want). If it's the latter, we could use an about:net-internals dump
(https://sites.google.com/a/chromium.org/dev/for-testers/providing-network-details)

[chro...@googlecode.com]

Comment #4 on issue 343856 by radiaraj...@gmail.com: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Hi Mate,

Let me elaborate,

Issue 1: Every time when I launch Chrome, its downloaded wpad.dat file from

the server instead of cache

Issue 2: Also its sending too many request more than 70- 80 request to
server to download

[chro...@googlecode.com]

Comment #5 on issue 343856 by mme...@chromium.org: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Every time you launch Chrome is expected.

70-80 requests, however, is not. A net-internals dump would be great.
Since it's happening when you start up, you probably won't be able to open
net-internals fast enough manually, so you'll need to create one by adding
a command line argument ("--log-net-log=filename", replacing filename as
appropriate).

Unfortunately, the code to redact cookies and credentials does not run when
logging this way, so there are privacy concerns. You can load the log in
about:net-internals itself to look for cookies, but logs contain a lot of
noise. My suggest is to run chrome
with "--user-data-dir=path/to/temp/directory" to create a new temporary
profile, so nothing will be leaked.

[chro...@googlecode.com]

Comment #6 on issue 343856 by Ryde...@gmail.com: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Hi, I am a colleague of Rajini who posted the question above.
I open the net-internals, from time to time I can see a lot of traffic
triggered to https://safebrowsing-cache.google.com/, will that causing the
traffic to the WPAD? I had exported the net-internals dump

Attachments:
net-internals-log.zip 115 KB

[chro...@googlecode.com]

Comment #7 on issue 343856 by mme...@chromium.org: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Thanks! Safebrowsing should not trigger extra proxy checks.

Looking at the net-internals log, I don't see any requests for the wpad
file. (I suspect the command line switch I suggested was not used, so we
don't have early events).

One thing that can trigger a bunch of WPAD requests is a bad PAC file, but
it looks like we've successfully loaded the pac file, and are indeed using
the proxy, so that seems unlikely.

[chro...@googlecode.com]

Comment #8 on issue 343856 by Ryde...@gmail.com: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Hi, I might had miss out the --log-net-log=filename part early. I had added
that and manage to get the dump out. Can you advise again?

Attachments:
capture.zip 99 KB

[chro...@googlecode.com]

Comment #9 on issue 343856 by mme...@chromium.org: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Thanks! That log does include two requests for wpad, which is one more
than needed, but as bad as the problem being described.

eroman: Are two requests for wpad expected at startup on Windows? There
are two PROXY_CONFIG_CHANGED events, I'm assuming due to how the code to
start watching for changes works.

[chro...@googlecode.com]

Comment #10 on issue 343856 by radiaraj...@gmail.com: Chrome Broswser -

WPAD file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Hi Mate ...

As like IE, Chrome can take it from the Cache.

Because if our WPAD server is down then CHROME will NOT work where as IE
still work,

Regards,
S Rajini

[chro...@googlecode.com]

Comment #11 on issue 343856 by joaod...@chromium.org: Chrome Broswser -

WPAD file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Issue 346209 has been merged into this issue.

[chro...@googlecode.com]

Comment #12 on issue 343856 by radiaraj...@gmail.com: Chrome Broswser -

WPAD file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Hi mmenke ...

Could you please assist.

Any way to get it from the cache or any plan. bcoz if our WPAD server is
down the it will be affected all users.

Regards
S Rajini

[chro...@googlecode.com]

Comment #13 on issue 343856 by mme...@chromium.org: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

In order to bypass proxy logic, the request for WPAD goes through its own
network stack, one that also doesn't have a cache, in addition to not using
a proxy. So there's no way, short of modifying chrome, to get it to cache
WPAD.

In general, this is probably the desired behavior - we don't know if we're
on the same network across browser restarts, so we should be re-requesting
WPAD.

You could use a local copy of WPAD, or push it to a more reliable server,
of course, but neither of those is an ideal solution, doubtless.

[chro...@googlecode.com]

Comment #14 on issue 343856 by radiaraj...@gmail.com: Chrome Broswser -

WPAD file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Thanks for your prompt response mate, appreciated.

Is there any option to CREATE CHROME GPO to get it from the CACHE directory
on the wpad file. This is only FUTURE REQUEST. I.E. who ever wants they can
enable GPO to take it from the CACHE DIRECTORY else it will be requested
every time to the server. Please CONSIDER and share your view. Thanks

Regards,
S. Rajini

[chro...@googlecode.com]

Comment #15 on issue 343856 by mme...@chromium.org: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

I'm not sure what you mean by a "cache directory". Do you mean one of the
per-profile caches that Chrome maintains, or one that you do? I'm assuming
the former. For the latter, you can use file URLs, and just distribute the
WPAD yourself.

I defer to eroman, but I think the use case for that feature is uncommon
enough, and the changes significant enough, that it's not something we're
currently interested in implementing.

[chro...@googlecode.com]

Comment #16 on issue 343856 by ero...@chromium.org: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

A general caching mechanism across chrome restarts is not something we
would add.

I believe your request is regarding the polling of the PAC script that
Chrome does (irrespective of the TTL on the PAC script response if it was
HTTP).

I haven't looked at the logs yet, but in theory this is Chrome's polling
policy (taken from source code):


// This is the default policy for polling the PAC script.
//
// In response to a failure, the poll intervals are:
// 0: 8 seconds (scheduled on timer)
// 1: 32 seconds
// 2: 2 minutes
// 3+: 4 hours
//
// In response to a success, the poll intervals are:
// 0+: 12 hours


I could imagine allowing a feature request for controlling the polling
policy via a group policy, but would want to see the data first if that is
even the concern.

Cheers

[chro...@googlecode.com]

Updates:
Labels: Enterprise-Triaged

Comment #17 on issue 343856 by atwi...@chromium.org: Chrome Broswser -

WPAD file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

(No comment was entered for this change.)

[chro...@googlecode.com]

Comment #18 on issue 343856 by radiaraj...@gmail.com: Chrome Broswser -

WPAD file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Hi Mate,

Another critical and Important assistance required from your end.

Details are explained below

Due to the primary proxy server in WPAD had HDD issue which was shutdown
and 1 of the applications using Google Chrome , it configured to use WPAD,
failed to work. Not like IE.

Support team need to manual point to Secondary proxy server in Chrome in
order to make the application work.

I have simulate to use a testing WPAD which the primary proxy server was
not reachable and used Google Chrome to access Internet and Intranet. Due
to proxy server unable to reach, there was around 20 seconds time out and
finally Chrome used 2nd proxy server defined in testing WPAD to access
internet and intranet.

The result showed that WPAD failover mechanism is working (only there is 20
second timeout), in Chrome as well as in IE (tested, same result).

It seems the application using Chrome could not bear 20 seconds timeout and
failed to work and needed to pointed to 2nd proxy server directly.

If Chrome can provide kind of auto failover configuration if primary proxy
unable to reach, it will straight to use 2nd proxy server defined in WPAD.
Can you help to explore this and revert the recommendation .

Please consider as CRITICAL and assist me

[chro...@googlecode.com]

Updates:
Status: WontFix

Comment #19 on issue 343856 by mme...@chromium.org: Chrome Broswser - WPAD

file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Going to go ahead and mark the original issue WontFix (Though, as eroman
said, may be worth thinking about making the polling policy configurable).
You've filed a new bug for the second issue (correctly).

[chro...@googlecode.com]

Comment #20 on issue 343856 by radiaraj...@gmail.com: Chrome Broswser -

WPAD file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Thanks mate,

Anyway if u consider in future release it will be greatful

[chro...@googlecode.com]

Comment #21 on issue 343856 by radiaraj...@gmail.com: Chrome Broswser -

WPAD file is always getting downloaded from the server instead of cache
http://code.google.com/p/chromium/issues/detail?id=343856

Team,


Any luck on controlling through GPO?
For WPAD script download?