Re: [9fans] 9ttp

[Bakul Shah <bakul@bitblocks.com>]

On Thu, 08 Sep 2011 09:56:10 PDT John Floren <john@jfloren.net>  wrote:
> On Thu, Sep 8, 2011 at 9:31 AM, erik quanstrom <quanstro@quanstro.net> wrot=
> e:
> >> > On Thursday 08 of September 2011 14:54:40 erik quanstrom wrote:
> >> > > On Thu Sep =A08 04:52:08 EDT 2011, 23hiro@googlemail.com wrote:
> >> > > > HTTP is technically different and not easily comparable to 9p. HTT=
> P is
> >> > > > not a good example of how to do things, but over high-latency link=
> s 9p
> >> > >
> >> > > =A0 =A0 =A0 with a single outstanding request
> >> > >
> >> > > > is much slower for getting files.
> >> > >
> >> > > there, fixed that for ya.
> >> >
> >> > is 9p windowable at all? is that implemented?
> >> >
> >> >
> >> >
> >> 9p has tagged requests.
> >
> > cf. /sys/src/cmd/fcp.c
> >
> > - erik
> >
> >
>
> I do not think it is acceptable to have to fork repeatedly merely to
> efficiently read a file. Also, as far as I can tell, exactly one
> program (fcp) does that.
>
> Can a single process have multiple outstanding requests? My
> investigations indicated not, but then again I may have mis-read
> things.

Is there a way to distinguish between files backed by real
storage & synthetic files? Seems to me that the server
wouldn't know if you pipelined multiple read/write requests on
a given connection (in-order delivery). May be the client can
do read-ahead of N blocks. But one issue with read-ahead /
write-behind is the problem of head of line blocking --
further non-r/w requests queue up behind them. That is why FTP
uses a control connection for all the commands & responses but
data is delivered on a fresh tcp connection.