Date: 01 Sep 1997 05:30:16 -0500 From: stephen farrell <sfarrell@healthquiz.com> To: Andrew Reilly <reilly@zeta.org.au> Cc: hackers@FreeBSD.ORG Subject: Re: Netscape Communicator 4.02b7 Message-ID: <87yb5hpbrb.fsf@phaedrus.uchicago.edu> In-Reply-To: Andrew Reilly's message of "Mon, 1 Sep 1997 18:13:01 %2B1000 (EST)" References: <199709010813.SAA00583@gurney.reilly.home>
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Andrew Reilly <reilly@zeta.org.au> writes: > > Mike Smith said: > >> Communicator forks to create the DNS helper process (a great idea, > >> IMHO) > > I don't know much (anything) about Netscape's DNS helper, but I > assume that it is some sort of DNS cache, to help avoid DNS traffic > of some sort. Why is it a good idea to have an application-specific > DNS cache, instead of tweaking named? The DNS helper is there because the nameserver lookup routines in unix are blocking (and cannot, as I understand it, easily be fixed to be asynchronous). As a consequence, a process which tries to do a nameserver lookup will appear to "hang"--i.e., not even refreshes on the windows--until the name server lookup either succeeds or times out. This can be very frustrating with a gui app like netscape. The DNS helper is there to do the nameserver lookups. This way the gui of netscape appears to remain "alive", and you can quit if you don't feel like waiting like 60 seconds for the nameserver lookup.
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