Re: [Caml-list] Re: scalable web apps

Re: [Caml-list] Re: scalable web apps

[Dario Teixeira]

Hi,

> Why would you use ocsigen to serve static files?

Simplicity.  A single server takes care of dynamic and static content,
making it easy to develop and administer.


> For corefarm.com we put all the files in amazon s3 and we just generate
> on the fly the url to retrieve them (adding the timestamp, signing the
> get parameters etc). 

Yes, S3 is awesome, but I reckon it would be overkill for what Sylvain has
in mind.  Moreover, it does represent an extra -- albeit small -- cost.

Cheers,
Dario Teixeira

Re: [Caml-list] Re: scalable web apps

[Gabriel Kerneis]

On Mon, Jul 26, 2010 at 05:10:01PM +0000, Sylvain Le Gall wrote:
> > Both Dbm and Sqlite lock the entire files which blocks concurrent uses,
> > isn't it a problem?
> 
> For sqlite, at least, it uses Lwt_preemptive.detach and sqlite3 contains
> the required caml_enter/leave_blocking_section(s). So Lwt should work
> without problems with sqlite.
> 
> I suppose it is the same for dbm.

No.  For dbm there is a separate daemon (ocsidbm) opening the file once
and serializing requests sent from and back to Ocsigen through a pipe.

Regards,
-- 
Gabriel

Re: [Caml-list] Re: scalable web apps

[William Le Ferrand]

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Why would you use ocsigen to serve static files?

For corefarm.com we put all the files in amazon s3 and we just generate on
the fly the url to retrieve them (adding the timestamp, signing the get
parameters etc).

My 2 cents,

william

2010/7/26 Sylvain Le Gall <sylvain@le-gall.net>

> On 26-07-2010, Dario Teixeira <darioteixeira@yahoo.com> wrote:
> > Hi,
> >
> >> I am creating an application with ocsigen that requires to serve a lot
> >> of .tar.gz as static contents.
> >>
> >> Do you think the "no Unix supports non-blocking mode" will cause problem
> >> in this case?
> >
> > I presume that application is related to the Oasis-DB initiative, right?
>
> You guess right ;-)
>
> > I wouldn't worry too much in that case.  First, because the Ocaml
> community
> > is not that big (yet) as to cause such heavy traffic.  Second, because
> > the set of tar.gz files is not that great (a few hundred, max?) and those
> > files will tend to be small.  If your server has enough memory, there's a
> > good chance many of the file blocks requested will eventually be buffered
> > in memory by the kernel, thus minimising expensive disc I/O.
> >
>
> There is indeed a good chance that the files end up in memory.
>
> Thank you for your remarks.
>
> Regards,
> Sylvain Le Gall
>
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-- 
William Le Ferrand

Speed matters : http://www.corefarm.com
Objects get social : http://www.sotokolan.com

Mobile : +33 6 84 01 52 92
LinkedIn : http://www.linkedin.com/in/williamleferrand

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Re: [Caml-list] Re: scalable web apps

[Dario Teixeira]

Hi,

> I am creating an application with ocsigen that requires to serve a lot
> of .tar.gz as static contents. 
> 
> Do you think the "no Unix supports non-blocking mode" will cause problem
> in this case?

I presume that application is related to the Oasis-DB initiative, right?
I wouldn't worry too much in that case.  First, because the Ocaml community
is not that big (yet) as to cause such heavy traffic.  Second, because
the set of tar.gz files is not that great (a few hundred, max?) and those
files will tend to be small.  If your server has enough memory, there's a
good chance many of the file blocks requested will eventually be buffered
in memory by the kernel, thus minimising expensive disc I/O.

Cheers,
Dario Teixeira