27 Sep
2012
27 Sep
'12
4:10 p.m.
On Thu, 27 Sep 2012, Mouse wrote:
It wouldn't be the first, second, third, or even tenth time I've seen
someone spec a machine much larger than required so that they could use it
for their own purposes. Machines that large are not exactly commodity
items, even today.
Your average static image file tends to be over 100KB now, which is going
to be difficult for an i486 based machine to keep up with. A 150MHz P5
with a basic 10/100 PCI NIC would probably handle it, but I wouldn't give
the task to anything slower, and as cheap as a 200MHz P54CS is, there
wouldn't be any point in using the slower processor. I ran a number of
486-based web servers into the late '90s, and they were just barely able
to keep up with average sized files back then.
Finding a 1U sized i486 machine with an ISA butterfly backplane chassis
would actually be no problem at all. These are still very common in
embedded applications where existing equipment relies on the ISA bus.
>>>> Serves almost exclusively static pages, max 1k hits per day. They
>>>> are looking at moving to a rackmount system. What does he spec?
>>>> Eight core Xeon with 96 gigs of RAM...
There is just no way someone is going to spec a
machine that large for
such a small task without some other background motive.
I disagree. There are a whole lot of sysadmins who do not really
understand such things; I'm sure lots of them would go "oh, I want a
webserver, let's look up some recommended specs for webservers" and find
a spec list by someone who's doing all sorts of server-side computation
(which, to be fair, is what a lot of people think of "a webserver" as
doing). Or they ask a friend who doesn't know the load in question and
answers hurriedly. Or, with slightly more competence, they find a wide
spectrum of answers and figure they don't know what's actually needed
and err on the side of extra power. A Socket 7
based machine such as a 200MHz Pentium P54CS with 128MB of
ram can even handle serving out 1k hits a day of static content...while
running modern software (BSD or Linux and Apache). I'm not sure I'd try
it today with a 486 based system due to latency and the bandwidth
limitations of the ISA bus (10Mb network cards),
Huh? 1K hits a day is less than one a minute. Unless the files it's
serving are truly ginormous, network bandwidth is not an issue; I'd
expect a 486-based system to be just fine. (Of course, that "less than
one a minute" is average; if traffic isn't approximately flat, it could
actually need to serve four or five pages a minute during peak periods.
I still have trouble seeing a 486 as insufficient.) The major reason
_I_ see for using something beefier is ease of obtaining it. Octo-core
Xeons with multiple gigs of RAM are trivial to order. 486s aren't,
especially if you want a 1U or 2U rackmount machine 'cause that's what
fits in your co-lo space. Latency, mayyyybe, if there's an expectation that
the whole page be
served with sub-second delay or some such silliness.
Even a one second delay while serving static content -is- a problem. Each
such delay adds to the total page load time, and it adds up in a hurry.
A modern Linux or BSD distribution typically expects gobs of memory (1GB+)
but I've found most will run well with 128MB so long as swap is available
(and you aren't running BIND). As much as I actually like the i486 arch
(power efficiency, among other things), a 486 based system will simply not
have enough physical memory available (generally no more than 32MB) and it
would craw to a halt with a modern OS while trying to swap stuff out to
disc while serving up pages via Apache.
Even if you could physically stuff 64MB of memory into a i486 based
system, that extra memory isn't going to be cached (no on-die cache with a
486) so it is going to be incredibly slow. Even most Socket 5 and Socket 7
based machines could only support 128MB (chipset limitations), even if the
processor itself could handle more.
I still work with embedded systems that use these very CPUs, so I'm
acutely aware of their limitations. In fact, those MicroVAX diagnostic
tape images I linked to were being served by a P200 with 128MB of ram (its
chipset can handle 512MB if I get around to hunting down a compatible
COAST module for the system).