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Re: A quota based lock

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On 09.08.2011 02:41, Eric Sosman wrote:
> On 8/8/2011 3:46 PM, Robert Klemme wrote:
>> On 08.08.2011 20:57, markspace wrote:
>>> On 8/8/2011 11:39 AM, Knute Johnson wrote:
>>>
>>>> No priority scheme will ever be truly fair. I'll bet you could get
>>>> pretty close without being too complicated. I'll think about it some
>>>> more.
>>>
>>>
>>> A simple priority system might involve multiple queues, where the high
>>> priority queues are serviced X times more than the lower ones.
>>>
>>> E.g., two queues. Queue A gets 10 jobs executed for each 1 job that
>>> queue B gets executed. But because queue B is always guaranteed to be
>>> serviced eventually, there is no starvation.
>>>
>>> This is a simple step up from round-robin service (which is what Eric
>>> proposed). There are many algorithms existing. Check out any text on OSs
>>> and job scheduling.
>>
>> Another idea would be to take the time a task has access to the
>> resource, sum up per task category and for the next task pick the first
>> one from the category which is furthest below its specified share
>> (percentage). Basically your approach measures executions and this
>> approach measures actual resource usage time.
>
> Yes, all these disciplines are plausible. My main piece of advice
> is KISS: Begin with the simplest possible solution, and elaborate it
> only when there's solid evidence it won't suffice.
>
> Sometimes the evidence can be gathered in advance: If you know
> things about arrival rates and hold times and latency requirements, you
> may be able to do a calculation that shows simple FIFO won't hack it.
> More often, given the inherent complexity and "brittleness" of software
> systems, you'll need to implement first and measure afterwards to learn
> about a solution's shortcomings. This can lead to discarding the first
> solution -- but, hey: It was the simplest one you could imagine, so you
> probably didn't expend inordinate effort on it, right? Much cheaper to
> jettison a simple approach than a complicated one.
>
> KISS.

Absolutely agree.  And we still need the OP to state his problem / 
requirements clearly.  Robert, what is it that you really need?  What is 
your use case and your ultimate goal?

Kind regards

	robert



-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

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A quota based lock Robert Stark <panxiaozhong@gmail.com> - 2011-08-08 00:13 -0700
  Re: A quota based lock Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-08 07:58 -0400
    Re: A quota based lock Knute Johnson <september@knutejohnson.com> - 2011-08-08 09:48 -0700
      Re: A quota based lock markspace <-@.> - 2011-08-08 10:00 -0700
        Re: A quota based lock Knute Johnson <september@knutejohnson.com> - 2011-08-08 11:39 -0700
          Re: A quota based lock markspace <-@.> - 2011-08-08 11:57 -0700
            Re: A quota based lock Robert Klemme <shortcutter@googlemail.com> - 2011-08-08 21:46 +0200
              Re: A quota based lock Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-08 20:41 -0400
                Re: A quota based lock Robert Klemme <shortcutter@googlemail.com> - 2011-08-10 09:36 +0200
                Re: A quota based lock Robert Stark <panxiaozhong@gmail.com> - 2011-08-10 04:40 -0700
                Re: A quota based lock Robert Klemme <shortcutter@googlemail.com> - 2011-08-10 18:55 +0200
                Re: A quota based lock Martin Gregorie <martin@address-in-sig.invalid> - 2011-08-10 19:26 +0000
                Re: A quota based lock Patricia Shanahan <pats@acm.org> - 2011-08-10 12:37 -0700
                Re: A quota based lock Robert Stark <panxiaozhong@gmail.com> - 2011-08-10 18:30 -0700
                Re: A quota based lock markspace <-@.> - 2011-08-10 19:17 -0700
                Re: A quota based lock Robert Klemme <shortcutter@googlemail.com> - 2011-08-11 12:32 +0200
          Re: A quota based lock Tom Anderson <twic@urchin.earth.li> - 2011-08-09 21:00 +0100
  Re: A quota based lock markspace <-@.> - 2011-08-08 07:58 -0700
  Re: A quota based lock Tom Anderson <twic@urchin.earth.li> - 2011-08-09 21:45 +0100

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