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Groups > comp.lang.java.programmer > #13561

Re: Pattern suggestion

From Arved Sandstrom <asandstrom3minus1@eastlink.ca>
Newsgroups comp.lang.java.programmer
Subject Re: Pattern suggestion
References <jmel0t$jrh$1@news2.carnet.hr> <WradnUhB_qEbaRfSnZ2dnUVZ_i2dnZ2d@earthlink.com>
Message-ID <b6Dir.3201$bU5.353@newsfe04.iad> (permalink)
Organization Public Usenet Newsgroup Access
Date 2012-04-15 13:57 -0300

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On 12-04-15 01:17 PM, Patricia Shanahan wrote:
> On 4/15/2012 7:11 AM, FrenKy wrote:
>> Hi *,
>> I have a huge file (~10GB) which I'm reading line by line. Each line has
>> to be analyzed by many number of different analyzers. The problem I have
>> is that to make it at least a bit performance optimized due to sometimes
>> time consuming processing (usually because of delays due to external
>> interfaces) i would need to make it heavily multithreaded.
>> File should be read only once to reduce IO on disks.
>>
>> So I need "1 driver to many workers" pattern where workers are
>> multithreaded.
>>
>> I have a solution now based on Observable/Observer that I use (and it
>> works) but I'm not sure if it is the best way.
> 
> I suggest taking a look at java.util.concurrent.ThreadPoolExecutor and
> related classes.
> 
> Try to minimize ordering relationships between processing on the lines,
> so that you can overlap work on multiple lines as much as possible.
> 
> Patricia

I agree. A problem description like this, java.util.concurrent is the
first thing that pops into my head. markspace mentioned map-reduce, and
there is specifically fork-join in Java 1.7 (they are similar insofar as
they are algorithms for dividing problems); I don't know if any of
that's involved because the line analysis may be independent. IOW, this
may not be a distributable problem, this may be millions of individual
problems.

java.util.concurrent will definitely have something. It could well be
that the processing of each line is isolated, and I'd assuredly be
thinking of ThreadPoolExecutor or something similar for managing these.
It has a lot of tuning options including queues. If the analyzers for
each line have to coordinate (and maybe there's some final processing
after all complete) there are classes for that too, like CyclicBarrier.

AHS
-- 
A fly was very close to being called a "land," cause that's what they do
half the time.
-- Mitch Hedberg

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Thread

Pattern suggestion FrenKy <frenky__nn@gmail.com> - 2012-04-15 16:11 +0200
  Re: Pattern suggestion Rui Maciel <rui.maciel@gmail.com> - 2012-04-15 16:04 +0100
    Re: Pattern suggestion Lew <noone@lewscanon.com> - 2012-04-15 08:15 -0700
  Re: Pattern suggestion markspace <-@.> - 2012-04-15 08:17 -0700
    Re: Pattern suggestion Arne Vajhøj <arne@vajhoej.dk> - 2012-04-15 22:01 -0400
  Re: Pattern suggestion Jan Burse <janburse@fastmail.fm> - 2012-04-15 17:41 +0200
    Re: Pattern suggestion Jan Burse <janburse@fastmail.fm> - 2012-04-16 00:37 +0200
  Re: Pattern suggestion Patricia Shanahan <pats@acm.org> - 2012-04-15 09:17 -0700
    Re: Pattern suggestion Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-04-15 13:57 -0300
      Re: Pattern suggestion Martin Gregorie <martin@address-in-sig.invalid> - 2012-04-15 19:56 +0000
        Re: Pattern suggestion Robert Klemme <shortcutter@googlemail.com> - 2012-04-16 09:55 +0200
  Re: Pattern suggestion Arne Vajhøj <arne@vajhoej.dk> - 2012-04-15 21:58 -0400

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