209729 - DNS: cache needs its own UI (display, clear button)

Status: VERIFIED WONTFIX

(Core :: Networking, defect)

Description

[benc]

DNS cache really needs its own UI. Right now, the only UI is clearing the cache
via "Offline" toggle.
Parity w/ other caches would include:

1- Clear button (not hidden in the behavior of another UI element). Offline has
many effects, some of which users do not want to enjoy all at once (for example,
closing all open connections disconnects chatzilla).

2- Presence in pref UI. DNS cache is not easily discoverable now because there
is no mention in Prefs, which is an important way people find features.

3- about:cache should display DNS cache entries.

Comment 1

[Mikel Ward]

I can't see this UI addition being much use once DNS is fixed
(see bugs including 151929 and 162871), and would rather not
have this.

You need not reply to this, I'm just registering my disapproval,
for whatever it's worth.

Comment 2

[Darin Fisher]

i agree.  the DNS cache expiration time will not be large enough to warrant such
a UI feature once the DNS rewrite lands.

Comment 3

[benc]

I'm going to respect the decision of the module owner, but make one last plea
here. I especially disagree with the point of view of comment #1; here is why:

DNS bugs have been a consistent in their frequency and pain. A big chunk of that
was because we didn't document our general behavior. I was covering DNS bugs for
some time before Darin started taking over open DNS bugs, so I might be speaking
from a more exenstive perspective than most. Now that Darin's re-write makes our
DNS behavior rational, I feel motivated to tackle that problem with a short
write-up.

But even with documentation about the cache, I think users should be able to see
what we have cached, and be given some control over it (especially since the
alternative has been for people to have to restart their client). People are
pretty dependent on our app now, restarts are painful, and in some cases,
dataloss events, so potentially as severe as crashing. 

If we had had the general class of UI features suggested in this bug the whole
time, we would have had much better traction on DNS bugs, and although Darin has
done a great job of lassoing up a big architectural mess (which is, at its
heart, UNIX's inability to provide effective name resultion for a persistent
client that accesss hyperlinked data), it does not obviate the benefits of
giving the user more transparency and control. We've given users shift-reload to
control bad content caching, I don't see why we can't give users the functional
equivalent for DNS caching.

Comment 4

[Christian :Biesinger (don't email me, ping me on IRC)]

>I think users should be able to see
>what we have cached, and be given some control over it 

hm, isn't the current status that mozilla never caches DNS entries for more than
one minute?

Comment 5

[Darin Fisher]

ben: there is a bug about making shift-reload bypass the DNS cache.  we should
do that, and that combined with online/offline toggling should be plenty.  i
don't want to add UI for this because i think for most users that is just bloat.
 it would increase the size of the product for little to no gain for the vast
majority of users.  about:cache is useful to web developers, but i don't think
the same argument can be made for something like about:dns-cache.  i hope you
can agree that it is at best a feature that would be nice for debug purposes. 
it could be an extension! ;-)

Comment 6

[benc]

VERIFIED:

Since we don't DNS cache forever anymore, the usefulness of this feature is
probably much smaller than before. Absent some kind of failure to clear
properly, you could troubleshoot your problems w/ a brief "cooldown", waiting
for the entries to time out.

I can live with offline-online, but I just think the button is too overloaded w/
functionality. Somewhere in 1.6, a right-click menu was added to toggle the
proxy mode setting.