why the need for speed? Because there are many such queries?

Split-second response time is of great value to the end user in this case. They really, really need to know the price of bananas right now. And yes, there are a lot of queries. Everybody loves bananas!

how important is the time between answers to the query from machine to machine?

For some commodities, it's easy to calculate a price and the worker nodes will finish their calculations quickly. For others it's tougher, and the worker nodes will have to churn for a while.

When the worker nodes can finish their tasks quickly, it's important that the inter-machine communication time doesn't become a bottleneck that degrades the apparent response time from the user's perspective.

Also note that because we need to know the total number of bananas across all nodes before any node can start calculating a price, we have a situation where the worker nodes as a group are only as fast as their slowest member. The same situation comes into play when calculating the final price to serve to the user -- we have to know what all the nodes want to charge before we can determine the final price. This is especially important if only one node has bananas.

So we need a strategy that has good worst-case-scenario performance.

is an (held)open session debtrimental?

I don't know. I've never done any sockets programming.

Probably it's better. When would it be bad?

In reply to Re^2: Rapid inter-machine communication on internal network by Anonymous Monk
in thread Rapid inter-machine communication on internal network by Anonymous Monk

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.