Re: Scaling noise

William Lee Irwin III
2003-09-03T19:55:14Z

On Wed, 2003-09-03 at 12:00, William Lee Irwin III wrote:
>> So as best as I can tell the proposal consists of using an orders-of-
>> magnitude slower communication method to implement an underspecified
>> solution to some research problem that to all appearances will be more
>> expensive to maintain and keep running than the now extant designs.

On Wed, Sep 03, 2003 at 01:11:55PM -0600, Steven Cole wrote:
> You and Larry are either talking past each other, or perhaps it is I who
> don't understand the not-yet-existing CC-clusters. My understanding is
> that communication between nodes of a CC-cluster would be through a
> shared-memory mechanism, not through much slower I/O such as a network
> (even a very fast network).
> From Karim Yaghmour's paper here:
> http://www.opersys.com/adeos/practical-smp-clusters/
> "That being said, clustering packages may make assumptions that do not
> hold in the current architecture. Primarily, by having nodes so close
> together, physical network latencies and problems disappear."

The communication latencies will get better that way, sure.

On Wed, Sep 03, 2003 at 01:11:55PM -0600, Steven Cole wrote:
>> I like distributed systems and clusters, and they're great to use for
>> what they're good for. They're not substitutes in any way for tightly
>> coupled systems, nor do they render large specimens thereof unnecessary.

On Wed, Sep 03, 2003 at 01:11:55PM -0600, Steven Cole wrote:
> My point is this: Currently at least one vendor (SGI) wants to scale the
> kernel to 128 CPUs. As far as I know, the SGI Altix systems can be
> configured up to 512 CPUs. If the Intel Tanglewood really will have 16
> cores per chip, very much larger systems will be possible. Will you be
> able to scale the kernel to 2048 CPUs and beyond? This may happen
> during the lifetime of 2.8.x, so planning should be happening either now
> or soon.

This is not particularly exciting (or truthfully remotely interesting)
news. google for "BBN Butterfly" to see what was around ca. 1988.

-- wli