[bind10-dev] shared memory data source: file-based (mmap) vs memory-only

[fujiwara at jprs.co.jp]

> From: JINMEI Tatuya / 神明達哉 <jinmei at isc.org>
> I personally prefer the file-based approach, because this can work as
> a persistent on-disk copy that enables nearly-zero (hot start case) or
> a few-to-10-ish seconds (cold start case, with some initial work) of
> start up time.  The major disadvantage is management overhead of the
> files and the risk of having corrupt on-disk images.
> 
> Do others have opinions/preferences on this?

I also prefer the file-based approach.

The approach resembles tinydns/djbdns.

The greatest advantage is that the DNS database at auth servers are
able to change in an instant. (using munmap/mmap)

I prefer generating another mmap file and rename it.
However, preparing new mmap file takes time.

-- 
Kazunori Fujiwara, JPRS <fujiwara at jprs.co.jp>