[bind10-dev] Suboptimal way of splitting XFR-out to messages

[Shane Kerr]

Michal,

On Mon, 2011-12-05 at 09:34 +0100, Michal 'vorner' Vaner wrote:
> Hello
> 
> On Fri, Dec 02, 2011 at 11:08:37AM -0800, JINMEI Tatuya / 神明達哉 wrote:
> > Personally I'm not convinced it's worth solving.  Even though names
> > cannot be compressed between different messages, in practice they
> > should be well compressed within their own messages.  So, roughly
> > speaking the additional overhead is the size of the DNS header part
> > (12 bytes each) that would not be needed if we made every message
> > really full.  If, hypothetically, a "suboptimal" message still
> > contained 65000 (instead of 65535) bytes of data, the overhead of the
> > header part is just 0.18%.  While the number of total messages also
> > matters in terms of processing overhead (in general handling two
> > messages would be more heavyweight than that for one message, etc), I
> > suspect it's still marginal in the total workload for the entire XFR
> > session.
> 
> Well, not only that. At last one full (uncompressed) name must live in each
> message.
> 
> However, this'll be few more bytes, so looking at it, it isn't probably that
> much.
> 
> So, should we drop the idea whatsoever, comment the code, or create a ticket in
> general backlog (so the question doesn't rise again and again)?

I think the best thing to do is probably to create a low-priority ticket
backlog mentioning this optimization, and why it is not very important.
Perhaps it makes sense to include a comment somewhere in the XFR-out
mentioning this as well?

--
Shane