[Gllug] OT: Tomcat & Apache mapping problem

[Rich Walker]

Joel Bernstein <joel at fysh.org> writes:

> On Thu, Mar 24, 2005 at 03:46:12PM +0000, Rich Walker wrote:
>> The -exec option to find is for use in emergencies only. Normally, you
>> want find ... | xargs ... : which will only start 3 processes, rather
>> than 1 per file...
>
> I still don't understand why this happens. Surely they should be
> executed sequentially?

They might be, but executing a lot of processes sequentially can bring a
(smaller) machine to a halt.
rw at zeus:/usr$ cd /etc
rw at zeus:/etc$ time find . -type f -exec ls "{}" ";" > /dev/null

real    0m32.323s
user    0m8.490s
sys     0m17.160s
rw at zeus:/etc$ time find . -type f -exec ls "{}" ";" > /dev/null

real    0m30.998s
user    0m8.270s
sys     0m19.130s
rw at zeus:/etc$ time find . -type f | xargs ls > /dev/null

real    0m0.567s
user    0m0.230s
sys     0m0.320s
rw at zeus:/etc$ time find . -type f | xargs ls > /dev/null

real    0m0.638s
user    0m0.290s
sys     0m0.300s
rw at zeus:/etc$

>> (yes, I have brought my machine to a grinding halt with the use of
>> find...)
>
> As have I. And I'm still convinced that this is very odd behaviour.

I guess it's "process spawn overhead". A bit like frogspawn, in that it
mysteriously appears and fills the pond...

:->

cheers, Rich.

>
> /joel
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