nscd cache problem

Jurek Bajor jurek.bajor at gmail.com
Sat Jul 3 08:25:15 UTC 2010

>Well, I have found that setting the interval to a longer time does
>indeed help a lot!
>However, the behavior of Firefox in resolving URL's  is still strange!
>If I click on a link, firefox spends almost a full minute to resolve the
>so while it is waiting (spinning), I use the gnome terminal to
>nslookup whatever-domain-it-was.com
>and it resolves it in less than a second. I look at firefox, and it is
>still trying to resolve!!
>Firefox seems to use some other way to resolve the url's domain - the
>painfully slow way!!
>Firefox has no config means of telling it how to resolve - so I'm at a
>loss as to it's behavior.
- of course I assume that your system config files are OK, like
[jb at localhost ~]$ cat /etc/hosts		localhost.localdomain localhost
::1		localhost6.localdomain6 localhost6
[jb at localhost ~]$ cat /etc/host.conf
multi on
order hosts,bind
[jb at localhost ~]$ cat /etc/resolv.conf
domain example.com
nameserver 111.222.333.444
[jb at localhost ~]$ ps aux |grep nscd
nscd      8652  0.0  0.1 150296  1328 ?        Ssl  04:34   0:01 /usr/sbin/nscd
jb        9924  0.0  0.0   4308   724 pts/0    S+   09:58   0:00 grep nscd
[jb at localhost ~]$ cat /etc/nsswitch.conf
# /etc/nsswitch.conf
# ...
passwd:     files
shadow:     files
group:      files

#hosts:     db files nisplus nis dns
hosts:      files dns

# Example - obey only what nisplus tells us...
#services:   nisplus [NOTFOUND=return] files
#networks:   nisplus [NOTFOUND=return] files
#protocols:  nisplus [NOTFOUND=return] files
#rpc:        nisplus [NOTFOUND=return] files
#ethers:     nisplus [NOTFOUND=return] files
#netmasks:   nisplus [NOTFOUND=return] files

bootparams: nisplus [NOTFOUND=return] files

ethers:     files
netmasks:   files
networks:   files
protocols:  files
rpc:        files
services:   files

netgroup:   nisplus

publickey:  nisplus

automount:  files nisplus
aliases:    files nisplus

[jb at localhost ~]$ cat /etc/nscd.conf
# ...
#	logfile			/var/log/nscd.log
#	threads			4
#	max-threads		32
	server-user		nscd
#	stat-user		somebody
	debug-level		0
#	reload-count		5
	paranoia		no
#	restart-interval	3600

	enable-cache		passwd		yes
	positive-time-to-live	passwd		600
	negative-time-to-live	passwd		20
	suggested-size		passwd		211
	check-files		passwd		yes
	persistent		passwd		yes
	shared			passwd		yes
	max-db-size		passwd		33554432
	auto-propagate		passwd		yes

	enable-cache		group		yes
	positive-time-to-live	group		3600
	negative-time-to-live	group		60
	suggested-size		group		211
	check-files		group		yes
	persistent		group		yes
	shared			group		yes
	max-db-size		group		33554432
	auto-propagate		group		yes

	enable-cache		hosts		yes
#jb	positive-time-to-live	hosts		3600
#jb 3600 x 24 x 30 = approx 1 month
	positive-time-to-live	hosts		2592000
	negative-time-to-live	hosts		20
	suggested-size		hosts		211
	check-files		hosts		yes
	persistent		hosts		yes
	shared			hosts		yes
	max-db-size		hosts		33554432

	enable-cache		services	yes
	positive-time-to-live	services	28800
	negative-time-to-live	services	20
	suggested-size		services	211
	check-files		services	yes
	persistent		services	yes
	shared			services	yes
	max-db-size		services	33554432
- look at your system services and permanently or temporarily disable
  unneeded services/daemons that interact with a network/Internet,
  like avahi-daemon, etc.
- in cases like this make sure  that you have up to date firefox , and that
  means install it from scratch (before that save your bookmarks),
  remove firefox, remove ALL leftover related directories so that no data
  or config caches are present (!), and install it again.
- start firefox and do not do any customized config yet; just try the same or
  any other URL to see if the problem persists
- do you have any custom firefox plug-ins installed , or any other stuff for
  that matter ?
  Remove that extra funcy stuff and see if it helps.
- now you can look at config issues
  - do you utilize any outside filter/proxy, like squid ?
  - do you config proxy in firefox ?
  - take a look at config via menu
  - take a look at config via url about:config
    Start with filter like ipv6 (you can turn it off/on and see the effect)
    Btw, that was once a cause of identical firefox/chromium problem in
    the past !
      network.dns.disableIPv6  TRUE
    Continue with filter like dns, and so on.
    Remember to restart firefox if you change config (just in case, to have it
    take effect).
- install other browser like Opera for testing and see if the problem persists.

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