[OSM-dev] mod_tile memory leak?

[Martijn van Oosterhout]

2008/6/5 Dylan Semler <dylan.semler at gmail.com>:
> On Wed, Jun 4, 2008 at 4:57 PM, Jon Burgess <jburgess777 at googlemail.com>
>> The system monitor is a little crude. Most linux systems that have been
>> running for any reasonable length of time will show nearly zero free
>> memory. This is expected behaviour[1][2].
>
> Yeah, I've heard it's crude and that measuring memory usage in Linux is not
> as basic as it would seem.

Usage is reasonable, however free memory == wasted memory. It's the
OS's job to make sure any available memory is used for something. What
you need to monitor is actual process size.

> Ahh, perhaps this answers it.  4 gigs of ram is enough for one z5 .meta
> tile, but two being rendered at the same time causes swapping.  I guess for
> some reason I had assumed that if it ran out of memory it would hold off
> from rendering new tiles until others were finished to avoid using swap
> space.  I don't know why I assumed this, it doesn't seem to make sense
> (though might it be more efficient this way?).

z5 covers a fairly large area, quite possibly it needed to load a
large chunk of the database which would use a lot of memory,
temporarily at least.

Have a nice day,
-- 
Martijn van Oosterhout <kleptog at gmail.com> http://svana.org/kleptog/