[Zope] Linux vs. UNIX vs. BSD

[Bill Anderson]

On Tue, 2002-08-20 at 12:20, sean.upton@uniontrib.com wrote:
> I'll second support for use of Debian.  We use it in a lot of production
> tasks on a bunch of servers and for development workstations.  That said,
> with some of our new boxes, we are using Debian, but compiling from source
> RedHat enterprise kernels (easier than patching stock kernel) to get better
> hardware monitoring, and more importantly, to get the O2 scheduler, which
> does have some crude CPU affinity support.  I believe this is one area where
> Linux has been a bit behind some other Unix varieties.
> 
> Though we haven't used it yet, as I understand it, CPU affinity is important
> to Python performance on SMP machines.   I expect that we will write or find
> a simple user-space utility utilizing the new system calls to bind a group
> of processes to a single CPU.  I think, in theory, this will allow us to
> successfully run two Zope instances on an inexpensive 2CPU machine, each
> instance bound to a respective CPU.

Sean,

You should look into the RedHat Advanced Server Kernel. The scheduler in
it is far superior to the standard, and includes CPU affinity. I'm not
sure how often python does context switches, but the RHAS kernel shows a
4X improvement in that regard. :)

I understand some/many of those changes can also be had in the -AA
patches to the 2.4. kernel as well. It also appears that if you want to
use XFS (my personal, and professional recommendation) you would be
better off using the -AA series. I have yet to complete the XFS
w/RHAS2.1 document. It is not trivial, yet.

Of course, you can get this by downloading just the kernel RPM, but if
you are aiming at a fast, high-availability production (SMP-)server, you
would gain much benefit by using the full RHAS2.1, either by purchasing
it, or building it from source rpms, whichever fits your budget better.
:)

Bill

-- 
Bill Anderson, RHCE
Linux in Boise Club                  http://www.libc.org
Amateurs built the Ark, professionals built the Titanic.
Amateurs build Linux, professionals build Windows(tm).