I was speaking of individual machines, not of the whole server farm. The total load served by Amazon or TM is quite impressive, however they use a lot of machines to do it. From what I know (more about TM than Amazon) though, the query rate handled by a single machine is not huge.

Yes, we really do use cooperative multi-blah systems at Yahoo, at least for some applications. Some of these more resemble a threaded programming model, some are more like event-based state machine models.

The most common place that I can think of where you'd like to use a design like this is when you have a service-oriented architecture and the server that originally receives a user request does little more than analyze the request and then make a number of sub-requests to other services. An event-driven state machine is generally the most efficient and scalable way to multiplex really large numbers of simultaneous connections. With the Apache pre-forked process model, each child is tied up for the whole time that you are waiting for the subrequests to return. There's a fairly low limit on how many active processes you can have before your machine ends up spending more time context switching than doing useful work.

In reply to Re^10: Why are people not using POE? by kscaldef
in thread Why are people not using POE? by johnnywang

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.