555819 - Firefox 3.6.2 slow to resolve domain names on Mac OS X

Status: RESOLVED INCOMPLETE

(Core :: Networking, defect)

Description

[Matthew Middleton (:zzxc)]

Numerous users on support.mozilla.com have reported that Firefox is slow to resolve domain names after upgrading to 3.6.2, hanging for several seconds at "Looking up <site>".  Affected users have confirmed that this happens instantly both in Safari and with the ping command in Terminal.

Users in Live Chat have confirmed that proxy servers are off in Firefox, that it's still slow after clearing the DNS cache, and that the problem still happens in a Namoroka build of Firefox.

Comment 1

[Mike Beltzner [:beltzner, not reading bugmail]]

Here are the bugs that we took in 1.9.2.2 in Networking:

https://bugzilla.mozilla.org/buglist.cgi?quicksearch=ALL%20status1.9.2:.2-fixed%20comp:networking

bug 494969
bug 542318
bug 547239

are the only ones in there that aren't public-suffix-list related.

Comment 2

[Honza Bambas (:mayhemer)]

I would guess it's bug 494969.

Comment 3

[Christian :Biesinger (don't email me, ping me on IRC)]

Which OS does this happen on?

bug 494969 is a little unlikely unless it'd only happen with certain sites (that use GSSAPI authentication).

Comment 4

[Boris Zbarsky [:bzbarsky]]

> Which OS does this happen on?

The OS field says "OSX", but I' being somewhat doubtful.  Hard to tell without any links in comment 0, though....

Comment 5

[Mike Beltzner [:beltzner, not reading bugmail]]

The bug, as reported by the release rapid response team (RRRT) is indeed OSX only, as indicated by the summary.

Comment 6

[[:Cww]]

http://support.mozilla.com/en-US/forum/1/627922 has lots of people complaining.

Comment 7

[Boris Zbarsky [:bzbarsky]]

Hmm.  Yeah, bug 542318 wouldn't happen on mac and bug 547239 wouldn't affect DNS.

Not sure about GSSAPI on Mac.... also seems dubious.

Can we get folks who can reproduce reliably to try branch nightlies, maybe?

Comment 8

[Mike Beltzner [:beltzner, not reading bugmail]]

Is there any networking diagnostic we can have them run that would give us more information about where the failure is taking place? Would running HTTP Live Headers help, for instance?

Comment 9

[Boris Zbarsky [:bzbarsky]]

It would certainly tell us if GSSAPI is involved, I'd think (unless I'm totally misremembering how this stuff works).

Comment 10

[Daniel Veditz [:dveditz]]

Did this really start in 3.6.2? I've been seeing slow lookups on Mac pretty much the whole 3.6 dev period. Maybe even 3.5.

(In reply to comment #8)
> Is there any networking diagnostic we can have them run that would give us more
> information about where the failure is taking place? Would running HTTP Live
> Headers help, for instance?

raw logs might be better
https://developer.mozilla.org/en/HTTP_Logging

Live Http Headers will only show the HTTP headers in the response, way above the dns lookups.

Comment 11

[:Gavin Sharp [email: [e-mail]]]

Have the people seeing this been asked to try disabling ipv6, per http://support.mozilla.com/en-US/kb/Firefox+cannot+load+websites+but+other+programs+can#IPv6 ? DNS issues on Mac has been a relatively common issue in the past (e.g. http://aplawrence.com/MacOSX/firefox_google.html ), and that's one of the potential fixes.

Comment 12

[Daniel Veditz [:dveditz]]

We'll re-evaluate "blocking" 3.6.x when we know more about the problem.

Comment 13

[Kai Engert (:KaiE:)]

Proposal to analyse the issue:
Prepare try server build(s), which are based on the release and have the mentioned networking fixes backed out, and ask affected users to test the try server builds.