Firefox DNS death

[kihjin]

The problem I'm having is a longstanding problem. I've had this problem ever since I upgraded to a 64bit system. I have a quad core now. Since then I've used 8.04, 8.10 and 9.04, and varying versions of firefox. Today I compiled Firefox 3.5.2 from source just for the purpose of testing this.

For the most part, browsing on firefox works. I don't have trouble accessing any sites, and then suddenly I'm no longer able to load any more sites. Firefox hangs on "Looking up..." I know for a fact that my network is still active, and a quick check with dig verifies that DNS is still working. Even if I press stop, close all my tabs, I can't load anything. The basic solution I've found is to close firefox, and reopen it. Right as firefox closes, there's a burst of data on the network.

I have not noticed any patterns or specifically how long after opening the browser this occurs. It does not happen on my 32bit dual core laptop (running 8.10 firefox 3).

I have tried various about:config tweaks with no success. Once firefox forgets how to do a DNS lookup, it's stuck like that until I exit completely.

I have no tried changing my DNS addresses, but, I don't see how that could be the problem since I don't experience this issue on my laptop, and it's only firefox that forgets.

Thanks.

[bchurchill]

I assume from what you wrote that you've tried the binary Ubuntu package already, and that didn't make a difference. Can you load things by IP address (eg google is http://74.125.65.103)? How about pages on localhost or your LAN?

[ptn107]

It does not happen on my 32bit dual core laptop (running 8.10 firefox 3).

Is your firefox 3 on 8.10 compiled from source or is it the stock 3.0.13?

[lovinglinux]

I know you said you have used some config tweaks but have you tried these:

- Changing the value of network.dnsCacheExpiration to a big value, so it doesn't check for DNS very often? I use 7200.

- Changing the value of network.dnsCacheEntries to a big value, so Firefox stores more DNS entries? I use 1000.

- Changing network.dns.disableIPv6 to true, so ipv6 is disabled? ipv6 is known to cause this kind of connection problem.

[kihjin]

Hey everyone. Thanks so much for the responses. They are all appreciated.

Before yesterday I had been running the ubuntu binary release of firefox 3.0. Every day I dealt with this dns issue, and I even researched the issue by searching these forums. I got used to closing firefox and "saving tabs."

I've been using firefox 3.5 from source, and the problem does not seem to occur nearly as much. Though, I've only been using it for less than a day, so we'll see how that goes.

I had not thought to try the IP address for google. I have now bookmarked that address, so when the problem occurs I can quickly try the IP and see what happens. What I have noticed with firefox 3.5 is that occasionally it will hang briefly on "looking up..."
At this point I quickly open the google IP in a new tab. Google loads up before the other tab even finishes resolving.

The laptop is using the binary install.

@Lovinglinux: Those are the config tweaks I had done in my binary 3.0 install. I used the following values:

network.dnsCacheExpiration = 3600
network.dnsCacheEntries = 500
network.dns.disableIPv6 = true

This actually seemed to make the problem somewhat more pronounced (in ff 3.0), so I didn't keep them for more than a few days. I did leave the ipv6 disabled, but the other two I set back to 0.

[kihjin]

Well after using Firefox 3.5 for a couple weeks, I can say that my problem still exists. At first, it seemed to have gone away, but it's been returning with a vengeance.

Basically, firefox locks up on a DNS query and then refuses to do anything else, load any other websites. It wont even complete the query its already doing. I have the google IP ADDRESS bookmarked. In most cases, opening this IP in a new tab does nothing! The tab just sits there, doesn't appear to load anything at all.

However, I am able to load localhost (my local apache) just fine.

The only solution that works every time is to completely close firefox and reopen it.

[winotree]

Of course, you've seen both of these?

http://kb.mozillazine.org/Network.dnsCacheExpiration
http://kb.mozillazine.org/Network.dnsCacheEntries

As I read them, it says to keep 20 entries in cache, each one for 60 seconds as default.

As you have it -- with both defaulted to zero -- it says to keep no entries in cache, for no length of time.

That is to say that Firefox has to look for each new DNS address which it then can't keep, then place it for storage in a place where it's told not to store it for any amount of time. Is this a correct reading?

Possible Remedy - enter defaults, live with it for two or three days, post results.

[kihjin]

I will give this a try.

However, DNS does not explain why I was not able to load a google IP (during the query lock)

http://74.125.65.103/

[kihjin]

So after using winotree's suggestion for a few days, it is obvious that my experience is better, only slightly.

This evening alone, I have experienced several dead-locking situations. Though, unlike in the past these dead-locking situations were mostly temporary, only requiring 30-60 seconds to "fix" themselves naturally.

Still I often find it easier to exit the browser, and try again. At which point all the pages load without effort.

[winotree]

Well, it's good news that something I offered helped someone -- bad news that it wasn't a true fix. I read a lot (have the time to do so) and haven't ever come across anything like what you're going through. You say it's been happening over a long period and across different distributions; you say you custom configured the last one as a test, is that correct?

Question -- have you used the same profile for all of them or not? If so, I'd bet that's your issue -- creating a new one should really help -- if not I'm truly at a loss as being any further help. Regardless, my best to you. Maybe we'll see each other around the forum??