[ka-Map-users] couple issues - maybe a cache bug

[Paul Spencer]

Ravi, it sounds as if you have not removed the existing tiles from  
the kacache folder or did not clear your browser cache after this  
change.  The browser will silently resize your tiles for you and by  
conveniently doubling the size of them, you have ensured that they  
line up with existing 256x256 tiles.

Cheers

Paul

On 22-Nov-06, at 5:28 PM, Ravi wrote:

>
> Regarding the risk size problem, I did some experimentation. I  
> increased the tile size to 512x512 and reduced meta tiles to 3 and  
> 3. Now I was able to generate the tiles however the rendering was  
> all wrong. The names of cities is horribly big and the map seems  
> completely messed up. Did anybody else try increasing tile size to  
> reduce disk size requirements?
>
>
>
>>> Problem 1
>>> ----------
>>> First I noticed that most of my tile cache images were 200-1000  
>>> bytes but they were taking 4096 bytes on the disk. Hence to  
>>> reduce disk size I increased tile size from 256x256 to 1024x1024.  
>>> I thought this would also reduce number of http requests and  
>>> speed up the application.
>>>
>>> After this change, the tile cache images generated were between  
>>> 2k-10k. However due to this change, ka-maps seems to come to a  
>>> grinding halt. Even for extent/zoom tiles that were present in  
>>> the cache, it took very very long time for ka-maps to finish  
>>> loading the maps. Any idea why?
>> Each tile is now 16 times bigger.  ka-Map will still try to load a  
>> minimum of 9 tiles and possibly 16 tiles, regardless of the  
>> viewport size.
>> Also, depending on the number of tiles per metatile you have  
>> configured, you are causing a lot of work for mapserver.  If  
>> you've kept the default values of 6 x 6, you are asking mapserver  
>> to render a map that is 6144 x 6144 which is larger than mapserver  
>> is normally configured to deal with (max is 2048x2048 I think).   
>> In general, I have not had good success asking mapserver to render  
>> images larger than this in any case.
>

+-----------------------------------------------------------------+
|Paul Spencer                          pspencer at dmsolutions.ca    |
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|Chief Technology Officer                                         |
|DM Solutions Group Inc                http://www.dmsolutions.ca/ |
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