[Koha-devel] "The Plack effect" benchmarked

[Paul Poulain]

Le 06/06/2012 13:36, Mark Tompsett a écrit :
> Greetings,
Hi Mark,
(answer to koha-devel, as it's of general interest)

> These results look good, but how much memory is on the machine you are
> testing this on? Would it have the same effect in a VM server type
> environment limited to 204MB? Is there an amount of memory which makes
> it behave at similar or worse speeds?
I think you missed a 8, and speak of 2048 and not 204MB :D

I haven't tested/checked memory, but what I know for sure is that it
costs only a small amount of memory.

Plack pre-load a lot of things that are loaded on every page by cgi-bin
anyway. So you would have 'spent' that memory at run time.

Depending on Apache configuration, if 5 ppl are requesting a page at the
same time, 5 cgi-bin are launched and 5x memory is consummed. So if you
run starman instead of plackup (starman being multi-thread, plackup
single thread), the result will be the same.

What we have to be *very* careful with is memory hole that result in an
always increasing memory consumption. In CGI mode, as everything is
freed/deleted after each page, any memory hole is painless. With plack,
memory hole will pile up and, at the end ... booom !


(All of this being not measured, so unguaranteed)
-- 
Paul POULAIN
http://www.biblibre.com
Expert en Logiciels Libres pour l'info-doc
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