[Tilesathome] another idea for more performance

[Damian Sulewski]

Am Montag, den 28.05.2007, 00:42 +0200 schrieb Frederik Ramm:
> Hi,
> 
> > 1. Clients do not upload zoom z+1 blank if zoom z is blank.
> 
> This has been implemented on 08 March by Deelkar (r2239).

and is not used currently as far as i understand this line correctly
 
#	$allempty = 0; # enable this line if/when serverside empty tile
methods is implemented. Used to make sure we generate all blank seatiles
in a tileset.
(i knew it was implemented)

> > 2. if server receives a blank_tile it removes all meta info and files
> > under it from disk, marking only this tile as blank.
> 
> This is, to my knowledge, not currently implemented. 
as you said "to my knowledge" looking in the trac would update your
knowledge ;-) at least for deleting tiles, metainfo is not checked in
the server by now
http://trac.openstreetmap.org/changeset/3017

> However it is a 
> rare case that an empty tile is uploaded where there was content before. 
> It does happen and needs to be handled, but executing a bunch of 
> "delete" requests each time an empty tile is uploaded might perhaps be 
> overkill - maybe run a periodic job that checks wheter tiles with 
> content exist below tiles without?

Comes a little late? Has proven its performance since 4 days?

> 
> > Removing all files from disk is done today also, because clients upload
> > a whole tileset.

Not if the tileset is empty, then (at least my client which is the
latest version) uploads only one z12 tile. (i use the settings in from
server, which i asume to be the best chosen)

> 
> Has Deelkar's optimization been removed or disabled using the 
> "renderFullTileset" option?

"RenderFullTileset=0"
as seen on svn


> > Removing meta info is in svn will be in asap.

When a blank tile is uploaded, where a real time was before, we need to
remove the meta info from the tiles_meta, since _details returns still
exists, and the tile can be found in latest.txt

> > For the switching phase we can decide on "vallidTileset" setting

see dissadvantages: when we would like to implement this solution and
whole tilesets will be uploaded then we have to decide if we only delete
the tiles which were uploaded, or all under them also.

Greetings,

Damian

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