970919 - Logged random "Server not found"

Status: RESOLVED INVALID

(Firefox :: Untriaged, defect)

Description

[igorsoarez]

Attachment: log.txt - HTTP activity log

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.70 Safari/537.36

Steps to reproduce:

Started four days ago, random URLs fail, ratio has been increasing.

Random URLs fail to load, for pages, assets, iframes. Firefox says "Server not found"

These URLs work in other browsers and curl. I have Beta, Aurora and Nightly installed, when a URL fails, it fails in all of them, but in other browsers it works.

Tried using system settings for proxy and no proxy at options but no effect.

Tried clearing cookies and cache but it doesn't work.

Tried toggling both network.dns.disableIP6 and network.dns.disablePrefetch also no effect.

I resisted creating this bug until I found a way to prove it - I have a log.

I'm on OS X 10.9.1, and I used this to create a log:

export NSPR_LOG_MODULES=timestamp,nsHttp:5,nsSocketTransport:5,nsStreamPump:5,nsHostResolver:5
export NSPR_LOG_FILE=~/Desktop/log.txt
./firefox

In the logs you should see that I tried accessing https://bugzilla.mozilla.org/ many times before it actually worked.
Can't figure out what is happening from the logs but it is weird to me that some timeout values are 0 and some are -1 milliseconds, dunno if related though.

I really would like to go back to using Firefox so I am very interested in fixing this, I'm 100% available to collaborate. I can collect more logs if this is not enough. Please help.


Actual results:

I tried accessing https://bugzilla.mozilla.org/ firefox shows "Server not found", after many tries it works again.
This happens randomly with many URLs throughout the day to the point that now I have to use another browser meanwhile.



Expected results:

What should have happened is that Firefox like the other browsers I have installed and like curl should be able to have loaded the page.

Comment 1

[igorsoarez]

More information:

If I leave the tabs that fail open and press refresh later (much later, like 20 minutes) those URLs work, but others still fail.

Comment 2

[igorsoarez]

Turns out it's a problem with my ISP's DNS. Chrome uses it's own DNS servers, don't know why curl never failed, but as soon as I changed my system DNS servers Firefox started working 100% again.

Sorry for opening this issue.