Re: [squid-users] How get negative cache along with origin server error?

On Sat, Oct 04, 2008 at 12:55:15PM -0400, Chris Nighswonger wrote:
> On Tue, Sep 30, 2008 at 6:13 PM, Dave Dykstra <dwd_at_fnal.gov> wrote:
> >> On Thu, Sep 25, 2008 at 02:04:09PM -0500, Dave Dykstra wrote:
> >> > I am running squid on over a thousand computers that are filtering data
> >> > coming out of one of the particle collision detectors on the Large
> >> > Hadron Collider.
>
> A bit off-topic here, but I'm wondering if these squids are being used
> in CERN's new computing grid? I noticed Fermi was helping out with
> this. (http://devicedaily.com/misc/cern-launches-the-biggest-computing-grid-in-the-world.html)

The particular squids I was talking about are not considered to be part
of the grid, they're part of the "High-Level Trigger" filter farm that
is installed at the location of the CMS detector. There are other
squids that are considered to be part of the grid, however, at each of
the locations around the world where CMS collision data is being
analyzed. I own the piece of the software involved in moving detector
alignment & calibration data from CERN out to all the processors at all
the collaboration sites, which is needed to be able to understand the
collision data. This data is on the order of 100MB but needs to get
sent to all the analysis jobs (and some of it changes every day or so),
unlike the collision data which is much larger but gets sent separately
to individual processors. The software I own converts the data from a
database to http where it is cached in squids and then converts the data
from http to objects in memory. The home page is frontier.cern.ch.

That article is misleading, by the way; the very nature of a computing
grid is that it doesn't belong to a single organization, so it's not
"CERN's new computing grid." It is a collaboration of many
organizations; many different organizations provide the computing
resources, and many different organizations provide the software that
controls the grid and the software that runs on the grid.

- Dave
Received on Tue Oct 07 2008 - 15:52:25 MDT