[Tile-serving] Improving Render Times

[Marcos Dione]

On Tue, Jun 18, 2019 at 03:30:13PM +0200, Christian Quest wrote:
> I patched renderd_list a long time ago to generate tiles recursively to use
> the cache more efficiently. Maybe it is time to finalize that and make a
> pull request ;)

    BTW, osm-tile-tools has a version of generate_tiles.py that does
exactly that. Unluckly is not yet suited for online rendering, it only
renders in batches.

> That's why we're currently upgrading OSM-FR servers from 64 to 192GB of
> RAM, and to 5TB of SSD (mix of nvme and SATA).

    I'm rendering from my laptop, and now that you mention memory, I lent
my 16GiB to my wife, so I'm running on 8 only :)

> In our case, a 128GB RAM server (FR style) hits a CPU bottleneck:
> http://munin.openstreetmap.fr/openstreetmap.fr/osm25.openstreetmap.fr/cpu.html

    I do too for ZLs 11 or so, everything before that is sloooow as hell.
what a pity, I just deleted my render logs, I could provide hard numbers
to back that up.

    last thing I noticed is that trying to split rendering to another
machine might need a lot of BW. over wifi it's imposibly slow, I'll try
eth soon.

    I hope all these tipshelp. Cheers,

	-- Marcos.

-- 
(Not so) Random fortune:
The technology industry sees itself as in rebellion against corporate
America: not corrupt, not buttoned-up, not empty. In fact, a tech company
can be as corrupt, soulless, and empty as any corporation, but being
unprofessional helps us maintain the belief that we are somehow different
from Wall Street.
	    -- Shanley Kane