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To: Andrew Reilly <reilly@zeta.org.au>
Cc: hackers@FreeBSD.ORG
Subject: Re: Netscape Communicator 4.02b7
References: <199709010813.SAA00583@gurney.reilly.home>
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From: stephen farrell <sfarrell@healthquiz.com>
Date: 01 Sep 1997 05:30:16 -0500
In-Reply-To: Andrew Reilly's message of "Mon, 1 Sep 1997 18:13:01 +1000 (EST)"
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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.