[OSM-dev] C++ implementation of the API

Tom Hughes tom at compton.nu
Mon May 26 15:07:46 BST 2008


In message <1211658532.3899.18.camel at test.asus>
          Joachim Zobel <jzobel at heute-morgen.de> wrote:

> Am Donnerstag, den 22.05.2008, 00:06 +0100 schrieb Tom Hughes:
> > > Writing Apache modules in C is hard, and I don't think using mod_cpp
> > > will make it much easier. Doing Apache modules in Perl (mod_perl has
> > API
> > > access including filters) is a lot easier.
> > 
> > Ye gads no. We want to keep the memory footprint under some sort of
> > control so mod_perl is a non-starter.
> 
> Everybody seems obsessed with low memory footprint. Why? Memory is
> cheap, and we are not planning an embedded system. What is the number of
> concurrent requests we need to handle?

I'm not obsesses with memory footprint, but with our current code
memory is far and away the biggest problem.

Currently we can handle about six simultaneous requests to the data
heavy API calls - that is basically map data downloads, gps data
downloads and potlatch calls.

The reason is that we have to allow about 600Mb or so for each call
and that quickly mounts up as you try and add extra simultaneous
accesses.

Factor in the fact that many of these calls may take a minute or
more and you have a serious limitation to the load we can support.

Of course we can just add hardware, but we should be able to reduce
the menory footprint dramatically as well.

Tom

-- 
Tom Hughes (tom at compton.nu)
http://www.compton.nu/




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