[Tilesathome] WG: Questions on tile updating process

[Sebastian Spaeth]

80n wrote:
>     Downloading the whole world for each tileset is out of question, of
>     course.
> 
> 
> Is it?  What captions are you currently downloading?  Cities, towns,
> villages? 

LowzoomPredicates =
node[place=town|city|country],way[boundary=administrative]
so it's 2 XAPI calls per z6 tile and there are 4096 z6 tiles to render.

Downloading from XAPI takes easily 30-240 seconds for those 2 calls
(with just using a 1.5 margin or whatever the t at h client uses by default).

> You can grab up to 10 x 10 degrees from XAPI which might be enough to
> reduce all but the most pathological edge case.
I'd hope that this would suffice. But still getting the data once and
just pointing the client to the local .osm source would be preferable.

I'll try to rerun the caption generation with more margin and see if I
get some timings. One of the problems is that I don't have enough
computing power for it, and making my work laptop unresponsible and
really noisy for an extended time is really not my preferred course of
action.

> If that isn't enough I could remove that bounding limit for just these
> tags until we find out what is really needed.

Let's try it with some larger bondary first and see how it looks like.
But as I said, my computing power resources are kind of limited. So I'd
really love if someone did something with a nice machine did something
along those lines:

1) increase the margin in general.conf
2) run the caption generation:

for x in `seq 0 63`; do
 for y in `seq 0 63`; do
  sleep 1
  date -u "+%Y%m%d %H:%M:%S" >> timestamp
  ./tilesGen.pl xy $x $y 6
  ./tilesGen.pl upload
 done;
done;

3) and report back some of the rendering times (and if we could get the
XAPI fetching times too that would be perfect.

spaetz