[Server-devel] Yummy incron

[Martin Langhoff]

On Wed, Jun 25, 2008 at 2:36 PM, Bill Bogstad <bogstad at pobox.com> wrote:
> I'm confused.   Won't the XS servers always have swap/paging space?

Paging is tolerable for batch processes, or for interactive stuff that
is not subject to timeouts (let the user wait while we bring
OpenOffice back from swap). Network services and swapping don't mix
well at all - they just timeout, which leads to users perceiving it as
"crashed", hitting "refresh" if available, and in our case perhaps
volunteering a "fix" in the form of a hard reboot.

Ouch.

If you look at apache and other web-services tuning strategies, the
*first* thing they do is ensure that the working set _never_ touches
swap. As soon as any network service gets swapped out, it's
unavailable for all intents and purposes.

Processes sitting idly in memory are wasteful unless they have a ton
of state in them to make them valuable. And even then, in many cases
they can just marshall that data, and pick it up later (lots of
exceptions for this - connection poolers for example).

We are working on what amounts to an embedded device - so we are going
to HTFU on memory usage :-)

cheers,



m
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 martin at laptop.org -- School Server Architect
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