in reply to Useful number of childs revisited [SOLVED]

Several years ago I was writing ETL for a very large datawarehouse (think top 10 databases in the world, although this was over a decade ago). And I did this on Sun's E10k frames which were multiple CPU (this pre-dates multi-core).

Because there are different ways of being 'bound', Memory-Bound, CPU-Bound, Network-Bound, Disk I/O-Bound, etc... the only way to truly know the optimal number of threads is by trial and error. At least with a program of any complexity. So you run tests and trials and you plot it out and it should be pretty clear where the sweet spot is.

--
“For the Present is the point at which time touches eternity.” - CS Lewis

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Re^2: Useful number of childs revisited
by karlgoethebier (Abbot) on May 08, 2015 at 17:43 UTC
    "...run tests and trials... should be pretty clear where the sweet spot is"

    Yes - what else should i do?

    But i think that you agree that the phenomenon i described is - to put it mildly (gelinde gesagt?) - surprising unexpected.

    Edit: Minor change of wording - i said this already.

    Thanks and best regards, Karl

    «The Crux of the Biscuit is the Apostrophe»

[reply]

      BTW: The simple cure for the problem would be to switch sleep for select( '','','', $timeout ), which would allow the timeout to be specified in fractional seconds; and set the default to something like 0.01. (Without adding a dependency upon Time::HiRes )

      With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
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[reply]
[d/l]
        "...to switch sleep for select( '','','', $timeout )..."

        Unfortunately i must admit that i don't understand this.

        Best regards, Karl

        «The Crux of the Biscuit is the Apostrophe»

[reply]

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