1432097 - Firefox ESR 52.5.2: Initial connection slowdown on "aged" profiles

Status: NEW

(Toolkit :: Safe Browsing, defect, P3)

Description

[heavymetal]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0
Build ID: 20171208114127

Steps to reproduce:

Profiles turn unusable in Firefox ESR 52 after some days of usage. For no obvious reason, a profile will suddenly break and no longer load the start page properly. Instead, the multiple connections to e.g. Google will hang for several seconds and massively slow down the overall startup process.

When starting in safe mode all is fine again. Creating a new profile also "fixes" the problem. Disabling/uninstalling addons does NOT fix the problem, neither does copying a known "good" profile over the broken one.
To make it clear again: After creating a plain new profile without any addons, I copied its folder to another location. After the profile broke I copied back the initial profile folder, yet this did not fix the startup issues.
What's the difference between normal and safe mode, besides disabling addons?


Actual results:

After startup, the requests of the initial start page connection hang for several seconds.


Expected results:

Requests should not hang.

Comment 1

[u408661]

Can you provide an HTTP log using the directions at https://developer.mozilla.org/en-US/docs/Mozilla/Debugging/HTTP_logging ?

Comment 2

[heavymetal]

Thanks for the link, I will create a log when/if the error reoccurs.

However, I currently cannot reproduce it. On Gentoo x86_64, the formerly broken profile is doing fine right now, without having changed anything.
On Debian x86_64, I had copied several broken profiles to a backup location, installed Firefox 58 locally (user home) and started with a new profile. Meanwhile Debian has updated the packaged Firefox to 52.6.0. I restored some of the old profiles and started Firefox 52, but the start page loads without any problems at all.

I'll keep watching both Firefox 52 and 58, and report back if the problem arises again.

Comment 3

[heavymetal]

Attachment: FF52 logfile of delayed startup (start page is google.de)

Logfile of delayed startup (https://www.google.de) created as follows:
export MOZ_LOG=timestamp,rotate:200,nsHttp:5,cache2:5,nsSocketTransport:5,nsHostResolver:5
export MOZ_LOG_FILE=/tmp/log.txt
firefox

This profile contains some addons and some modified settings in about:config, I hope the log is somewhat useful for you anyway.

Comment 4

[heavymetal]

Attachment: about:support info

Comment 5

[Honza Bambas (:mayhemer)]

Thanks for the log!  I can only see delays (up to ~4-5s) caused by classification for significant number of channels.

Could you please add nsChannelClassifier:5 to the list of modules and retry?  That could reveal further more what's happening.  Thanks!

Comment 6

[Honza Bambas (:mayhemer)]

Also, can you please verify if this is still reproducible with the latest Firefox Nightly?  Please backup your profile first before you run it!  See https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles for location and management.

Comment 7

[heavymetal]

Attachment: log with nsChannelClassifier:5

Log created with MOZ_LOG=timestamp,rotate:200,nsHttp:5,cache2:5,nsSocketTransport:5,nsHostResolver:5,nsChannelClassifier:5

Comment 8

[heavymetal]

I didn't try nightly, but 58.0.1 is currently running fine.

Comment 9

[Honza Bambas (:mayhemer)]

Thanks, there is unfortunately only that enough information to confirm it's the classifier to blame.  Francois?

Comment 10

[heavymetal]

Not sure if this helps, but I disabled anything related to safebrowsing that can be enabled/disabled in about:config. That speeded up the startup process, but there were still freezes lasting for some seconds.

Comment 11

[François Marier [:francois]]

We've fixed a lot of performance-related issues in the URL classifier in the lead up to 57. We'd need to dig into the various improvements we've made but they're likely to be quite large for an ESR point release.

Comment 12

[Honza Bambas (:mayhemer)]

(In reply to François Marier [:francois] from comment #11)
> We've fixed a lot of performance-related issues in the URL classifier in the
> lead up to 57. We'd need to dig into the various improvements we've made but
> they're likely to be quite large for an ESR point release.

Yes, I didn't expect we would do any performance uplifts to ESR 52.  Just wanted to confirm this was likely fixed in newer versions.

Thanks.

Comment 13

[heavymetal]

Funny wording. I really wouldn't call this a request for "performance uplifts" in older versions.
Firefox ESR has been working flawless for years, it seems one of the latest updates just broke something.
If it were a performance problem, new profiles would also be affected.
I switched to non-ESR so it actually doesn't matter for me anymore, but IMHO: weird rationale of handling bugs...