[Tilesathome] Some First Day Stats

[Christopher Schmidt]

On Thu, Nov 08, 2007 at 11:11:59PM -0500, Matthias Julius wrote:
> So we have to think of ways to fill it up again to see when we can
> bring the server to its knees ;-)

Well, right now I'm moving 1.4TB of data off the disk where tiles are
currently hosted  -- I made 120GB of space earlier, but I figured we
could use more. So right now, the server seems to top out somewhere
between 800/900 tilesets an hour, while I'm copying other data off the
disk at 200MB/s.

So, there are definitely limits to what is doable, but the current rate
of tile edits is about 250 an hour (1000 tilesets every four hours);
based on deelkar's script: this means that we have probably more than
four times the capacity to keep up with 'live' editing of tiles. 

Of course, this brings up something deelkar was talking about earlier,
which is that so long as there is a long outstanding queue,
multithreading via different rendering processes works, but as soon as
that's no longer the case -- that is, most tilesets being requested are
immediately given out to renderers -- we want to multithread the actual
rendering itself, since that results in faster turnaround time to users. 
Even if the queuing server is instantaneous, if each tileset takes an
hour to render, we can't make the turnaround time get faster.

However, I do think it means that we can start filling in the gaps that
we have, perhaps by having a 404 handler which queues tiles, like
mapnik's rendering currently does. I think that would probably be handy
until we get the tileset back up to 'full' like we had it before.
(Certainly, it would make me feel better to know that if I bump into an
empty tile, something will automatically be taking care of it for me.

Regards,
-- 
Christopher Schmidt
MetaCarta