Bind V9 and hosting lots of Domains

[Kevin Darcy]

Jim Reid wrote:

> >>>>> "Gareth" == Gareth Houghton <ghoughto at netcom.ca> writes:
>
>     Gareth> We currently host 220,000 domains.
>     Gareth> Will Bind V9 be more efficient for us?
>
> I can't see how. After all, no matter what name server you use, it
> will still have to keep track of the same number of domains. Demand
> loading zones should eventually be do-able in BIND9, but whether this
> would be "more efficient" or not is anyone's guess. Keeping the
> unreferenced zone data out of the name server will certainly save RAM
> and VM. The overhead and complications of pulling this stuff on demand
> out of a database or whatever could well generate inefficiencies and
> complications elsewhere. Swings and roundabouts.... I suppose the
> outcome will depend on the metrics you use to define "efficiency".
>
> Each zone will need a struct dns_zone (zoneinfo in BIND8). For small
> zones, this could well be bigger than the actual zone data. So
> shunting that data off to disk might not save you significant amounts
> of RAM anyway.

 But if the "pre-loaded" zone information isn't touched very often, it'll
be paged out of memory (on any *real* OS :-). So that would be a big win.
And you wouldn't need to store a full-blown "zone" structure for a
demand-loaded master zone (I'm assuming we're talking mainly about master
zones here) -- you'd just need to store a small datum, e.g. a hash key,
which uniquely identifies the zone and then it can load the rest on
demand, including any ACL's, forwarding information, also-notify's,
etc...


- Kevin