359425 - When network connections settings are high, some searches hang

Status: RESOLVED WORKSFORME

(Firefox :: Search, defect)

Description

[Marc Auslander]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1) Gecko/20061010 Firefox/2.0
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1) Gecko/20061010 Firefox/2.0

With the changes made by tweak network settings power mode, with or WITHOUT pipeling selected, there are long delays in some web fetches, and some like the one above hang firefox completely - only an external kill works.

This is NOT a tweak network settings extension complaint - the underlying engine seems to have a bug with is exposed by the settings it makes.

Reproducible: Always

Steps to Reproduce:
1. use tweak network settings and request power mode. (disabling pipeline makes no difference)
2.visit the url above.
3.

Actual Results:  
firefox becomes unresponsive


this does not happen with 1.5.7

i've seen a number of complains in the forums about V2 hangs - I suspect his may be the source.

Comment 1

[Anders Conbere]

If this is not a tweak network settings extension bug, then there needs to be a bug filed based on the actual Firefox settings.  There is very little the developers can tell you about what tweak network settings is doing (as it could be modifying things that you don't know about).  Until this has some kind of text case or a refined set of settings changes that make this occur there isn't anything we can do. And this bug is invalid.

Comment 2

[Marc Auslander]

I can no longer reproduce this with the url provided.

Sigh

Comment 3

[Marc Auslander]

I can sometimes reproduce.  Try it.

Superstition - clear the cache before trying to improve changes of the failure.

Comment 4

[Anders Conbere]

This really isn't helpful though because we don't know what network tweak is doing. If this can be reduced to a problem with a setting in about:config then it can be tested.

Comment 5

[Marc Auslander]

First - I'm still trying to reproduce this on a clean profile.  The darn thing is intermittent.  If you want to defer this until I can report failure in a clean (except for the network prefs) system, I'll understand.  I know there is a belief that the freeze problems are not in the base system.

The prefs in the failing settings are

user_pref("network.http.max-connections", 40);
user_pref("network.http.max-connections-per-server", 16);
user_pref("network.http.max-persistent-connections-per-proxy", 16);
user_pref("network.http.max-persistent-connections-per-server", 16);

Comment 6

[Anders Conbere]

So what needs to happen now is getting network tweak completely out of the picture and changing the summary to reflect that.  If what you're seeing can be replicated with changes in those settings then there's triaging that we can do.

Comment 7

[Marc Auslander]

As requested (I hope) I started again with a new profile.

I then used about:config to change the four network settings listed above.

I then tried to visit the URL listed above, and hung.  Firefox was using 44% of the machine and was unresponsive.

If there is any way I can get you more info (a dump, for example) I'd be happy to try.

Please remember that this may be a bug caused by high connection settings, or it may be a bug exposed more easily by high connection settings.

Lots of people are reporting freezes.

Comment 8

[Anders Conbere]

If you can narrow it down to one / two /three / or all of the settings that are exposing this behaviour it would be terrific.

Comment 9

[Marc Auslander]

I will try but

If a developer can reproduce and break in with a debugger, wouldn't that be a way to proceed?

Comment 10

[Marc Auslander]

Its always hard to tell with an intermittent but:

I believe that the relevant settings are max-connections-per-server and
max-persistent-connections-per-server

when both are 16 I see the failure.

It appears that setting either lower prevents the failure.  I am guessing that its the persistent connection setting, and the if the regular setting is low it puts a bound on the persistent value as well.

It makes some sense, given that this only happens with some sites, that persistent connections are involved.

Is there any way to see if the site uses persistent connections?

Comment 11

[Wayne Mery (:wsmwk)]

still see problem ?

Comment 12

[Marc Auslander]

I never tried again with 2.x.  I'm running 3B5, which has higher settings by default, and have not seen any problems.  IMHO, this should be closed.