Kubuntu should include nscd DNS cache deamon by default

[mumme]

Binary package hint: kdelibs

As Kde doesn't have a built in DNS cache daemon it makes konqueror, and other apps that use KdeIO unnecessary slow.
Browsing a typical portal page reduced load time from
25 s and unreadable in at least 20 s
to
10 s while the page was readable in 4 s
when I installed nscd.

Please see Mr Macieira answer at Kfm-devel
http://lists.kde.org/?l=kfm-devel&m=116557063409802&w=2

I do disagree that this page is a corner case, or that nobody uses slow DNS servers. But thats another question.

/ Fredrik

[mumme (fredrik-mumme)]

Tim Ri pointed out that I should attach some sites that apear slow for me so you could test them.

Also the most probable cause that I experience konqueror slow is that my ISP DNS doesnt support IPv6.

So a easy GUI way if setting KDE_NO_IPv6 environment setting would perhaps make people more aware of the DNS issue.

Anyways here are my findings:
Slow sites in konqueror (without nscd) measured during refreshing the page
http://tv4.se/ 38 sec
http://www.cnn.com/ 23 sec
http://svt.se/ 35 sec
http://www.youtube.com/ 15 sec
http://www.kde-apps.org/ 15 sec
http://formula1.com/ 38 sec
http://shots.osdir.com/index.php?distro=451 19 sec

Same sites with nscd running, same environment, and measured with page refresh
http://tv4.se/ 12 sec
http://www.cnn.com/ 15 sec
http://svt.se/ 15 sec
http://www.youtube.com/ 9 sec
http://www.kde-apps.org/ 8 sec
http://formula1.com/ 17 sec
http://shots.osdir.com/index.php?distro=451 4 sec <-- notice this result !!! compared to 19 sec

Same sites with nscd running and KDE_NO_IPv6=true, same environment and measured with page refresh
http://tv4.se/ 10 sec
http://www.cnn.com/ 11 sec
http://svt.se/ 11 sec
http://www.youtube.com/ 5 sec
http://www.kde-apps.org/ 4 sec
http://formula1.com/ 11 sec
http://shots.osdir.com/index.php?distro=451 2 sec <-- even better

Same sites without nscd running but with KDE_NO_IPv6=true, same environment and measured with page refresh
http://tv4.se/ 14 sec
http://www.cnn.com/ 13 sec
http://svt.se/ 19 sec
http://www.youtube.com/ 9 sec
http://www.kde-apps.org/ 4 sec
http://formula1.com/ 15 sec
http://shots.osdir.com/index.php?distro=45 9 sec

Also the statistics of nscd --statistic
....
passwd cache:

            yes cache is enabled
            yes cache is persistent
            yes cache is shared
            211 suggested size
         216064 total data pool size
           1728 used data pool size
            600 seconds time to live for positive entries
             20 seconds time to live for negative entries
          20094 cache hits on positive entries
              0 cache hits on negative entries
            322 cache misses on positive entries
              5 cache misses on negative entries
             98% cache hit rate
             18 current number of cached values
             58 maximum number of cached values
              1 maximum chain length searched
              0 number of delays on rdlock
              0 number of delays on wrlock
              0 memory allocations failed
            yes check /etc/passwd for changes
....

Hope it helps..

/ Fredrik

[Wit Wilinski (wit-wilinski)]

What about using pdnsd for that? It was designed as a DNS cache server and works pretty efficiently.

The only thing, that DNS updates would have to modify /etc/pdnsd.conf and put only 127.0.0.1 to /etc/resolv.conf

[Rich Johnson (nixternal)]

Closing due to inactivity, and the links that worked for me that were provided were pretty fast. I don't run a dns cache daemon, however I did disable ipv6 a while ago when it was stated this was a slowdown for Konqueror as well. If you feel this is still and issue, I urge you to reopen this report with further information. Thank you.

[mumme (fredrik-mumme)]

This is still an issue.

What do you mean by inactivity?
I thought you (Kubuntu) were better suited to discuss and find out the best solution and I thought the KDE guy who actually wrote the http/Dns code opinion and suggestion to use a dns cache should be enough arguments.

If you dont want dns cache deamon then fine by me, but I think Kubuntu should provide some easy way for users to speed up their environment. Like in a GUI for KDE_NO_IPV6 or something
I recently had problems with nscd, it shutdown unexpectedly, and instantly my browsing went from feeling quite fast to beeing slow as a dog. even google took 4-5 seconds to load

I googled up another solution
http://ubuntu.wordpress.com/2006/08/02/local-dns-cache-for-faster-browsing/

Webpages of today usually contains a lot of external references, layout images, css files, scripts ordinary images etc.
without a DNS cache Kioslaves sends a DNS lookup request for EACH and EVERY one of those resources, combine that with a DNS that doesnt support IPV6 and you have a recipe for a very slow environment.

[Rich Johnson (nixternal)]

NSCD will not make it into main and get installed out of the box for a multitude of reasons, one being the issue you noticed and another big issue is its interaction and breakage/disruption of samba, which more of our users use than NSCD. KDE has made it clear they won't be including the NSCD like caching in their KIO slaves since NSCD already provides this. And if you read through that entire thread, they also talk about glibc bugs as well. So this is why I also closed this bug, an NSCD wishlist item won't make it.

Only thing I can think of would be a GUI interface to turn on/off ipv6. Now if you want to, reopen a new report for such a feature against kubuntu-meta or kubuntu-default-settings, and I will confirm it, and see if what we can do. How does that sound?

[mumme (fredrik-mumme)]

Ok Im sorry that I pushed so hard for nscd in this bug, I don't care which dns cache deamon Kubuntu uses.
I just went on Mr Macieira suggestion.

I you rather use another one like pdnsd or dnsmasq or some other dns cache please do.

Anyway in the meantime I posted a new wish bug per your suggestion regarding the KDE_NO_IPV6
https://bugs.launchpad.net/bugs/119598

I hope that was what you meant.

Regards
Fredrik Johansson