Re: dns and software, was Re: Reliable Cloud host ?

[Michael Thomas <mike () mtcc com>]

On 03/01/2012 08:58 AM, William Herrin wrote:
> On Thu, Mar 1, 2012 at 10:01 AM, Michael Thomas<mike () mtcc com>  wrote:
> > On 03/01/2012 06:26 AM, William Herrin wrote:
> > > The even simpler approach: create an AF_NAME with a sockaddr struct
> > > that contains a hostname instead of an IPvX address. Then let
> > > connect() figure out the details of caching, TTLs, protocol and
> > > address selection, etc.  Such a connect() could even support a revised
> > > TCP stack which is able to retry with the other addresses at the first
> > > subsecond timeout rather than camping on each address in sequence for
> > > the typical system default of two minutes.
> >
> > The effect of what you're recommending is to move all of this
> > into the kernel, and in the process greatly expand its scope.
> Hi Michael,
>
> libc != kernel. I want to move the action into the standard libraries
> where it can be done once and done well. A little kernel action on top
> to parallelize connection attempts where there are multiple candidate
> addresses would be gravy, but not required.

connect(2) is a kernel level call just like open(2), etc. It may
have a thin wrapper, but that's OS dependent, IIRC.

man connect 2:

"The  connect()  system  call connects the socket referred to by the file descriptor..."

Mike