Re: [9fans] "FAWN: Fast array of wimpy nodes" (was: Plan 9 - the next 20 years)

[Eric Van Hensbergen <ericvh@gmail.com>]

On Sun, Apr 19, 2009 at 2:58 AM, John Barham <jbarham@gmail.com> wrote:
> I certainly can't think ahead 20 years but I think it's safe to say
> that the next 5 (at least doing HPC and large-scale web type stuff)
> will increasingly look like this:
> http://www.technologyreview.com/computing/22504/?a=f, which talks
> about building a cluster from AMD Geode (!) nodes w/ compact flash
> storage.  Sure it's not super-fast, but it's very efficient per watt.
> If you had more cash you might substitute HE Opterons and SSD's but
> the principle is the same.
>

We thought this was the future several years ago
(http://bit.ly/16ZWjc), but couldn't convince the company that such an
approach would win out over big iron.  Of course, if you look at Blue
Gene, it's really just a massive realization of this model with
several really tightly coupled interconnects.

>
> Apparently they use the above cluster to implement some type of
> distributed memcached style cache.
>

I'm not convinced that such ad-hoc DSM models are the way to go as a
general principal.  Full blown DSM didn't fair very well in the past.
Plan 9 distributed applications take a different approach and instead
of sharing memory they share services in much more of a message
passing model.  This isn't to say that all caches are bad -- I just
don't believe in making them the foundation of your programing model
as it will surely lead to trouble.

    -eric