1195592 - FF 40.0.2: Disqus comments take much longer to load than prev version.

Status: RESOLVED FIXED

(Web Compatibility :: Site Reports, defect)

Description

[MarkRH]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0
Build ID: 20150812163655

Steps to reproduce:

For example: http://crooksandliars.com/2015/08/maher-im-going-give-hillary-clinton-one

Thread on Mozillazine: http://forums.mozillazine.org/viewtopic.php?f=38&t=2954909

Is this really the intended behavior to take this much longer. 41 Beta does the same thing.


Actual results:

After scrolling down to comments, a spinner appears and it takes over 10 seconds for the comments to appear.  Even with a new, clean, profile.


Expected results:

In Firefox 39, the comments did not delay in loading and were visible much sooner.

Comment 1

[ekerazha]

I can confirm this issue.

Disqus is *extremely* slow to load in Firefox 40. This is a serious issue.

Comment 2

[ekerazha]

Related issue? Bug 1195201

Comment 3

[Michael Bennett]

Initially, I reported this to Disqus last Friday as a bug with both FF versions 40.0 and 40.0.2.

However, after testing this "slow download of Disqus comments" problem on my old laptop I discovered that it's not confined to just these two Firefox versions -- it also fails with version 39.

Comment 4

[ekerazha]

(In reply to Michael Bennett from comment #3)
> Initially, I reported this to Disqus last Friday as a bug with both FF
> versions 40.0 and 40.0.2.
> 
> However, after testing this "slow download of Disqus comments" problem on my
> old laptop I discovered that it's not confined to just these two Firefox
> versions -- it also fails with version 39.

I just rechecked Firefox 39.0.3 and it works fine for me. Google Chrome works fine too.

Instead, Firefox 40 is extremely slow when it tries to load Disqus... and sometimes it just keeps loading forever.

Comment 5

[Michael Bennett]

>
> I just rechecked Firefox 39.0.3 and it works fine for me. Google Chrome
> works fine too.
> 
> Instead, Firefox 40 is extremely slow when it tries to load Disqus... and
> sometimes it just keeps loading forever.

I suspect the difference could be that my 'old laptop' using FF version 39 is running Windows XP. (Chrome and IE are okay.)

As I mentioned, I am seeing the same slow loading as I do with my new laptop running Windows 8.1.

Also, in the Disqus forum people have also seen this issue with Ubuntu and an iMac.

Comment 6

[ekerazha]

(In reply to Michael Bennett from comment #5)
> I suspect the difference could be that my 'old laptop' using FF version 39
> is running Windows XP. (Chrome and IE are okay.)
> 
> As I mentioned, I am seeing the same slow loading as I do with my new laptop
> running Windows 8.1.
> 
> Also, in the Disqus forum people have also seen this issue with Ubuntu and
> an iMac.

Is there any reason why on Windows XP we should also see this issue with Firefox 39?

On my Windows 10 system:
- Internet Explorer: OK
- Chrome: OK
- Firefox version < 40: OK
- Firefox version >= 40: SLOW, BUGGY

Moreover, the more comments there are, the more it slows down... when there are a lot of comments, Firefox 40 seems to load forever.

Comment 7

[MarkRH]

Well, looks like something has happened, perhaps on the Disqus end or other change in site code? It doesn't lag in 40.0.2 anymore, at least not here: http://crooksandliars.com/2015/08/maher-im-going-give-hillary-clinton-one like it was. Not sure why the difference in behavior between 39.0.3 in 40+ previously.  Time will tell if this is resolved.

Comment 8

[Michael Bennett]

Working on my end as well.

Looks like it may have been a fix with Disqus as I am still using Firefox 40.0.2.

Yay!

Comment 9

[Karl Dubost💡 :karlcow]

Switching to resolved according to previous comments.

Comment 10

[Burak Yiğit Kaya [:BYK]]

We did change something yeah (Disqus here). We were using `requestAnimationFrame` for each rendering pass to keep the browser responsive. Apparently with this version, Firefox got smart enough to throttle that when the iframe is not visible so we switched back to `setTimeout`.

Comment 11

[ekerazha]

I can confirm that the server-side change made by Disqus fixed the issue with Firefox 40.

Comment 12

[Kohei Yoshino [:kohei]]

I guess this was caused by Bug 1145439.

Comment 14

[Kohei Yoshino [:kohei]]

https://developer.mozilla.org/en-US/Firefox/Releases/40/Site_Compatibility#HTML

Comment 15

[Burak Yiğit Kaya [:BYK]]

Is there an RSS feed we can follow for https://developer.mozilla.org/en-US/Firefox/Releases/ ?

Comment 16

[Kohei Yoshino [:kohei]]

For the site compatibility docs, the feed is currently available at
https://developer.mozilla.org/en-US/docs/feeds/atom/tag/FxSiteCompat

But I'll move those docs from MDN to FxSiteCompat.com soon. The new site will offer a feed.