The browser will not load websites after 8 and a half days of continuum use




3 years ago
3 years ago


(Reporter: bluelf, Unassigned)


38 Branch
Windows 7

Firefox Tracking Flags

(Not tracked)



(2 attachments)



3 years ago
When the user:
1. Installs version 38.0.5 of the Firefox browser on a x64 Windows 7 platform
1. Loads about twenty webpages (keeps them open in tabs)
3. Uses the browser lightly for 8 and a half days without closing the websites
The following occurs:
After about 8 and a half days, new websites will not load anymore and current opened webpages will not be refreshable.

Note: This can be a blocker for operations that involve a constant flow of information (surveillance or financial institutions)

Workaround: Broswer needs to be restarted.

Reproduction rate: This was reproduced 5 out of 5 times.


3 years ago
Priority: -- → P1


3 years ago
Group: core-security
Severity: blocker → normal
Priority: P1 → --

Comment 1

3 years ago
Andrei, are the pages where you experience this private or can you share them? It would certainly be helpful if we could look at the pages ourselves to determine what the problem might be. 

What does the memory usage of Firefox look like over time? Is it increasing over the period of days that you have the pages open? If you can open a new window/tab and navigate to about:memory, you can measure and generate memory reports which might be helpful in diagnosing the problem. Note the reports will contain urls which you may consider sensitive. In about:memory, you can also free memory by performing a GC (garbage collection) or CC (cycle collection). Does the memory use drop significantly and do the web pages begin responding again?

We've had situations in the past where GC/CC were not performed on background tabs and perhaps this is happening again in your situation.
Flags: needinfo?(bluelf)

Comment 2

3 years ago
Hi! First of all, most of the pages vary from trial to trial so it could be that mentioning them will not help all that much.
Here are some from the last trial of reproducing the issue:
And a few sites that are behind my VPN network, I'm sure you can't access them, but a link usually goes something like this:

I have not monitored the amount of memory Firefox uses over the days it says open. Right now it's fluctuating around 810,000k
I did not observe any hangs in Firefox before it stops being able to load sites. My machine has 8Gb of RAM, and the other browser I'm using at the same time with Mozilla, Chrome, has a lot more tabs open, thus making it a much bigger memory eater.
Flags: needinfo?(bluelf)

Comment 3

3 years ago
Created attachment 8625708 [details]
A memory report after a few hours of use

I attached a memory report after a few hours of use with the described webpages
This sounds like a resource leak of some kind, but it may not be a memory leak -- Windows has other kinds of resources that you can run out of that won't show up in a memory report.

Some web pages are pretty active when you just leave them there, for example social sites like twitter and facebook are constantly checking for status updates. Other pages are completely static once loaded--if those are causing leaks over time that would point our investigation in a different direction. Some sites look pretty static as they sit there, but actually have fairly active ad-updating running. Can you give us any information about your internal trac site, whether it's more static (in which case we can ignore it) or more active, and if the latter what kinds of things it might be doing while it sits open. The public sites on your list we can check ourselves.

Comment 5

3 years ago
Our internal trac site is static, nothing updates without a refresh. Also it has no ad banners of any kind.

Comment 6

3 years ago
Created attachment 8627105 [details]
A memory report after the problem has occurred (no site can be loaded)
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