Re: Bug#459664: this bug/#459664 - host.conf: "multi on" appears to be default
On Tue, 8 Jan 2008, Justin Pryzby wrote:
> #459664 - host.conf: "multi on" appears to be default
> http://bugs.debian.org./459664
>
> I just checked the source. The default (when no host.conf exists or
> includes no multi line and none of the overriding environment
> variables are sert) seems to be "multi off"; however debian
> distributes a conffile with default content "multi on", so the
> behavior default is different from the behavior default in glibc.
> It's not clear to me if this justifies an explanation in the manpage,
> as this same situation occurs with some regularity; perhaps the
> conffile should instead include comments; in particular, a commented
> line for each value that is left at the default (and of course an
> uncommented line for each value that's changed therefrom).
It is in fact a little bit inconsistent that glibc has a default and
we override it in /etc/host.conf by default.
I don't quite understand the rationale given by the manpage, namely:
multi Valid values are on and off. If set to on, the resolv+ library
will return all valid addresses for a host that appears in the
/etc/hosts file, instead of only the first. This is off by
default, as it may cause a substantial performance loss at sites
with large hosts files.
Are there really many systems using large hosts files these days?
Do they really suffer from bad performance by using "multi on"
(which, by way of /etc/host.conf, is the default in Debian).
Could we make "multi on" the default in glibc and remove host.conf entirely?
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