[cups.development] [RFE] STR #3685: cups uses BrowseInterval as the interval for browsepoll...

[Jon Peatfield]

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It is documented but BrowseInterval is used for both the time delay to send
out advertisements and also to poll servers when using browsepoll.

In our environment we have servers which poll the real servers and send
adverts out to different groups of usrs machines.

We want to stick with sending out the adverts at the standard interval (or
client machines may time them out), but we don't want to poll the servers
quite so often.

Now this isn't in fact a big problem for us but recently we noticed that
if one of the 'real servers' goes away for a short time then all the
printers from that server vanish.  This is because cups-polld sets the
expiry lifetime of the printers to 2 * poll-interval rather than using the
BrowseTimeout value.  So missing two polls (or one if you are unlucky) will
cause the printers for that server to be removed.

Of course they all get added again once the polled server comes back, but
in our case a samba server will have noticed the queues going away and
quietly dropped the windows printer drivers... and they don't
automatically come back when the printers get added.

I think that this is partly samba's fault for dropping the drivers just
because the printers go away from cups, but it could affect other clients
and cups probably should allow for more than a couple of poll intervals to
be missed since a server might just be taking a while to reboot (we have
several boxes which take much longer that 60 seconds to count their
memory).

What I think I want is a BrowsePollInterval to allow the setting of the
cups-polld interval and perhaps a way to specify the timeout that
cups-polld puts into the browse messages it sends to cups.

So far I've only checked the source of cups-1.3.7 (well actually from the
redhat enterprise 5 srpm), so this may have already changed in a newer
version.

I'd be happy to offer a patch to add BrowsePollInterval and alter the
timeout it uses if that might be of any help.

Link: http://www.cups.org/str.php?L3685
Version:  -feature