1749138 - Firefox crashes after some day of activity, when thousands of tabs are present (unloaded) in session store

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[mirh]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:96.0) Gecko/20100101 Firefox/96.0

Steps to reproduce:

I have a ton of tabs open, and I only usually restart firefox every week or so to update the beta.
Once I begin to "hammer memory usage" (say, opening a lot of twitter profiles in parallel) there's a point when something breaks.
Some extensions (like reddit enchantment suite) stop to work, loading is quite slower (though that could just be the result of paging happening more frequently) and tabs seldom crash.
But this is all nice and dandy, and I couldn't really fault the browser for the immense atrocities I put it through.

Actual results:

Unfortunately, the last time this happened, the fresh restart was different.
More or less my last 4-5 days of "tab activity" where nowhere to be found. In other words, every tab I had opened after a certain time was missing (history still registered my activity just fine though).

Expected results:

Even more crashing during browsing would have been fine.
But not loosing data this way, if I can explain.
...
I understand my bug report is very hazy, but something must get stuck around session restore AFAICT.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Firefox::Session Restore' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Andrei Purice]

Hey mirh,
I tried reproducing this issue on the latest versions of Firefox Nightly 97.0a1 (2022-01-10), beta 96.0b9 and release 95.0.2 but couldn't reproduce it.

Testing with a fresh new profile could help. You can find more about creating a new profile here : https://support.mozilla.org/en-US/kb/troubleshoot-and-diagnose-firefox-problems#w_6-create-a-new-firefox-profile .
If possible, you can test this issue on the nightly build as well. Download the build from : https://www.mozilla.org/en-US/firefox/nightly/all/ .

Comment 3

[mirh]

I mean, this is an issue with memory pressure and heavy tab loading...
I'm absolutely sure nothing of this would ever happen if I hadn't hundreds of websites loaded at a time, and I cannot really fault anybody not to have foreseen this.. But still it wouldn't hurt if you could fix the issue.

https://crash-stats.mozilla.org/report/index/2ca4564a-8ace-4344-8e63-7203c0211211
https://crash-stats.mozilla.org/report/index/13113901-4420-4704-a605-95a930211223
https://crash-stats.mozilla.org/report/index/3e559d02-0f68-4058-8ad2-0229e0220108

These are some of the last crash reports I had, just for context. I'm not saying *that* is the reason for loosing my activity, though it should be somehow related to blowing up every possible usage metrics.

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:dao, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 5

[mirh]

So, I just lost the last 8 days of opened tabs. Again.
(though to be fair I was kinda trying to fish the problem as much as possible, in order to presumptively better report here)

https://crash-stats.mozilla.org/report/index/a4fd7485-ba22-45d0-af6d-7f0d60220124
Besides the last crash that took down the entire browser (I guess it's the usual OOM), I also noticed about:crashes had some prior unsent crash reports (even though I never really noticed them).

https://crash-stats.mozilla.org/report/index/53fd019f-e40d-4f7a-8bba-54a430220125
https://crash-stats.mozilla.org/report/index/d080534e-2089-4b2b-845f-9ad7d0220125
They happened some days after session store "failed upon me", but hopefully they can still help to find clues.

Comment 6

[mirh]

Well, I feel like the situation is worsening.
Here I was (quickly) scrolling the library/history, exactly to add a little comment here, when the whole browser came down.
https://crash-stats.mozilla.org/report/index/3328c15c-a706-480c-af8f-17e020220129

Fair enough, really, as I said I cannot blame software when I mistreat it so much.. but it turns out "tab tracking" didn't even last a couple of days.
Tuesday night was the last start time (basically when I wrote the last comment), and more or less on Wednesday evening it stopped "recording".

https://crash-stats.mozilla.org/report/index/8aa15c4d-8cec-4cc4-bb0a-50d7f0220129
https://crash-stats.mozilla.org/report/index/b2384e4d-ca8b-49dd-965b-fafee0220129
https://crash-stats.mozilla.org/report/index/52a771dd-7b4d-4467-96c7-ede0a0220127
These are the not-that-much-critical crash logs that happened during that session.

As a mater of fact, in the relatively short period before it got stuck, I could count north of 4 thousands unique URLs I had visited.

Comment 7

[mirh]

Attachment: Glimpse from Process Explorer

I had half an idea this could have been due to the simple tab group extension, but it turns out it wasn't.

https://crash-stats.mozilla.org/report/index/b686d7a5-39f6-4dc2-82b7-9ddab0220207
Also, today crash had me wait a hanged process for 4 hours before happening.
(to reiterate, I'm not saying it's the OOM problems to be causing the issue with the loosing tabs/sessions, but I lowbrow feel like they may share a similar cause)

Comment 8

[mirh]

https://crash-stats.mozilla.org/report/index/235e3b06-2b14-4fcf-9ea3-059bf0220221
The browser really doesn't like when I scroll quickly the history in the library.

Comment 9

[mirh]

This is getting more and more appalling.
I don't think this is about out of memory problems anymore, since not even half a day passed between me restarting the browser to "freshen" it.. and yet I lost all this afternoon.

Comment 10

[mirh]

https://crash-stats.mozilla.org/report/index/16ffe302-2405-4b33-9dc1-3422d0220304
And here we are again, with another crash after waiting for hours for the browser to get unstuck like in comment 7.

Is sessionstore the only important place where lz4 compression is used? Could there be some race condition with its writing, or data structure that can break when it becomes too big (uncompressed it's 112 MB here)?

Comment 12

[mirh]

Here the browser got stuck after the OS went into a memory pressure situation (I'll grant it wasn't really the smartest move on the shed to start a rendering with a fully bloated browser opened, but still it shouldn't happen that it just hangs for a day)
https://crash-stats.mozilla.org/report/index/2bb03281-672d-4e1d-8420-66def0220315
This is a mild crash that happened somewhere after some hour while the main browser was still stuck
https://crash-stats.mozilla.org/report/index/a58bb56b-e864-4a31-81ac-09ef40220315
Last but not least this is what I got from the entire browser crashing, after I used procexp to kill the biggest thread I could find. For some seconds it got unstuck and seemed to resume working (the tab I had under my eyes didn't even crash, and I could even interact with it more or less normally) but then everything closed down.
https://crash-stats.mozilla.org/report/index/589bd81f-5590-42d3-8475-864cf0220315

I hopefully nailed down the lost tab problem.. but where could I show my grievances for the crashing?
Bug 1755168? Bug 1667476? Bug 1475518?

Comment 13

[mirh]

https://crash-stats.mozilla.org/report/index/fc4d25e1-98fa-41e4-8ad9-c34330220322
I was trying to restart firefox early.. But every "about" tab was only returning a blank screen.
The browser console still somehow worked, and shortly before the crash I spotted an NS_ERROR_FAILURE.. in customElement.js, about something parseXULToFragment something.

Comment 14

[mirh]

https://crash-stats.mozilla.org/report/index/bp-1acc2a0b-e604-4955-87b2-fa8980220322
Sigh, I cannot even last 6 hours of browsing now.

Comment 15

[mirh]

Attachment: Process Explorer of the stuck x64 thread

https://crash-stats.mozilla.org/report/index/978cb57f-9bc1-4520-9fad-717510220325
Ok so, this crash was funny, in the sense that I could see it coming.
"About" pages, the browser console, and even certain information dialogs were just blank, and tabs were a bit funky in loading.
Then out of the blue, boom, everything came down. The crash signature is a bit different from the previous ones.

But the interesting thing is what happened now that I switched to firefox x64.
https://crash-stats.mozilla.org/report/index/4e5791d4-7b1c-4bfc-8516-fb9510220327
I still crashed eventually after hanging for a hour (and after two days of intense hammering just to test if the situation couldn't have improved) but I lost no tab whatsoever this time.

So, I don't know, I'm somewhat happy finally.
But these crashes are so reproducible by now that they seem a problem worth tackling.

Comment 16

[mirh]

https://crash-stats.mozilla.org/report/index/79cca000-80f4-497b-83b5-cdf320220410
Mhh, well, two weeks have passed, and the only odd thing I can report was this little offside... It wasn't even bad given I didn't notice it until I checked the crash reports window.

I don't know what may have happened (99end having some little fix, or perhaps just restarting once "cleanly" the 64 bit version?), but even some committed torturing for like 5 days had me and my pagefile yielding before any nastiness.
So farewell, I guess.

Comment 17

[mirh]

Version 101 hasn't been great..
https://crash-stats.mozilla.org/report/index/ece4ee65-5e4d-4ee8-b67b-6eebe0220529
https://crash-stats.mozilla.org/report/index/9837cb2a-f15a-4819-a845-8e64e0220529