434180 - Slow page loading in multiple tabs

Status: RESOLVED INCOMPLETE

(Core :: Networking: HTTP, defect)

Description

[Dotan Cohen]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b5) Gecko/2008050509 Firefox/3.0b5
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b5) Gecko/2008050509 Firefox/3.0b5

When opening multiple tabs in Firefox, any tab that takes a long time to load will prevent the other tabs from loading. It appears that no new tabs can be loaded when one tab is waiting for the server to reply. The browser is still responsive, but the pages do not load, which differentiates this bug from Bug 413390 and Bug 406567.

Reproducible: Sometimes

Steps to Reproduce:
1. Go to a page with many links to different servers, such as slashdot.org
2. Open several links in new tabs
3. ????
4. Profit..... no, wait!

Actual Results:  
Browser will not load new tabs when one tab hangs.

Expected Results:  
Browser would continue to load new tabs even if one hangs.

Comment 1

[charles anathema]

I also experience this exact bug. It is a VERY old Firefox bug that has plagued me through the versions.

A similar related bug is that once you click on a link, the page you are viewing does not change to the new page loading, but internally it already has, so clicking any links or anything does nothing, and if you stop the loading the page turns blank. I believe this is in the same area of tabs freezing the UI while loading (though the core UI stays responsive as above, just page loading etc freezes up)

Comment 2

[Mikko Rantalainen]

Does it make any difference if you disable automatic checking for attack sites and forgeries at Tools - Options - Security? I've heard that Firefox could have problems with its internal sqlite database with that feature enabled (at least on linux), though it could be only a rumour...

Comment 3

[Dotan Cohen]

Makes no difference. I actually had that database erased and the feature disabled when I reported the problem. I just checked with the feature enabled, no change.

Comment 4

[Boris Zbarsky [:bzbarsky]]

Dotan, I assume this is a regression from Firefox 2?

Comment 5

[Dotan Cohen]

Actually, no, this problem was noticeable in all versions of Firefox 2 as well. A recent slashdot article in which many people complained about this behaviour catalyzed this bug report:
http://tech.slashdot.org/article.pl?sid=08/05/17/1219210

If need be, I can parse that page and quote the particular mentions of this behaviour.

Comment 6

[Boris Zbarsky [:bzbarsky]]

Ah, ok.  Confirming, then, but this is not likely to block Firefox 3 at this point...

I wonder whether someone can construct a testcase that shows this problem.  You can use http://landfill.mozilla.org/ryl/slowResponse.cgi?time=60 as one of the URIs: that will wait 60 seconds before responding.  Changing the 60 to some other timeout can be used as needed.

Comment 7

[Dotan Cohen]

This does not need to block Firefox 3, I agree.

In Portable Firefox 2.0.0.14 on Windows XP at the university I opened slowResponse.cgi in three tabs, then google in a fourth. Google came up before slowResponse.cgi. So this may be a regression from Firefox 2. I tried with network.http.piplining and network.http.proxy.piplining set to both the default "false" and set to "true". In both cases the issue did not manifest. Could this possibly be a problem with my home ISP, and not Firefox? Opera does not seem to suffer from this condition.

Comment 8

[Boris Zbarsky [:bzbarsky]]

I wonder whether the real issue is slowness of the server response or slowness of the DNS resolution...  When you hit this issue, does closing the tabs after the pages have all loaded and then opening them all again right away still show the problem?

Comment 9

[Dotan Cohen]

Interestingly, the problem does not show the second time. I can load the last tab even when the previous tabs are loading, so long as it has been opened before. I did not notice this before.

Comment 10

[Boris Zbarsky [:bzbarsky]]

Hmm.  What if you clear your cache before the second load?

Comment 11

[Dotan Cohen]

For some reason, even when I visit sites that I've never visited before, I cannot reproduce the bug.

I made a page, stored locally, with that links to the slowResponse.cgi page with 62, 64, 66, and 68 seconds. I middleclick on each of them, to load them in background tabs, then create a new tab and load up a page that I've never visited before. The new page arrives before the slowResponse pages arrive. This is in contrast to the situation that I had 3 days ago, and which I've noticed in the past, and which many people have complained about on slashdot. I will leave the bug NEW for now, and I will try to reproduce it and see what else I can learn. If I do not succeed in reproducing the bug then I will mark it as WORKSFORME.

Comment 12

[Wayne Mery (:wsmwk)]

Is this still seen with firefox 3.6 or 4.0 beta?

Comment 13

[Dotan Cohen]

Still reproducible in 3.6, I can not check the 4.0 betas at the moment sorry.

Comment 14

[Mats Palmgren (inactive)]

Dotan, can you reproduce the problem in Firefox 7 or newer?

Comment 15

[Dotan Cohen]

Mats, I am still on Firefox 6 due to extension compatibility issues.

On Firefox 6 in safe mode I cannot reproduce the issue right now. However, I am _certain_ that I was affected by this bug as late as last Friday. It is very intermittent. I have no problems with you closing the bug until I can provide more details regarding reproducibility, however seeing how other people can still confirm its presence I lean toward keeping it open.

Comment 16

[Phoenix]

Resolved per whiteboard, feel free to reopen if problem still here in latest Firefox releases