[OpenLayers-Users] Optimal tile size for tilecache

[Adrian Popa]

Hello Christopher,

Thanks for your reply.

I am using cgi  mode (because it's been the easiest to setup). How do 
you recommend I run tilecache? I don't want to precache my whole map 
because most of the zoom levels (in some areas) don't give much 
information. I could precache some zoom levels and let the details be 
rendered on the fly, when needed...

I'm not using metatiles (or at least I think I'm not using them)... I 
don't really know what metatiles are and what they are supposed to do. 
Maybe a point to the right documentation would be ok...


The tile loading process goes like this - when I change my zoom the 
center tiles are loaded pretty quickly (even if they haven't been 
cached) - in about half a second, but the edges of my image take about 
~5 seconds to load. I thought it might be a limitation of my browser - 
on how many connections it can keep - so I added a lot of connections  
(20 per server) both on my browser and my web server (20 processes 
listening). The speed limitation is visible even when the tiles (for 
that area) have been cached. I thought that by increasing the tile size 
the browser would make fewer requests and the page would maybe load 
faster...

Thanks,
Adrian



Christopher Schmidt wrote:
> On Mon, Oct 19, 2009 at 02:30:44PM +0300, Adrian Popa wrote:
>   
>> Hello everyone,
>>
>> Just wondering - what would be a good tile size to be used for 
>> tilecache, so that the client will not do a lot of queries to the server 
>> (seems they take quite a while), and at the same time would not load too 
>> much information that is not used (areas of tiles which are outside the 
>> viewable area).
>>
>> My web clients use screen resolutions starting from 1200x1024 (and 
>> usually run the page in full screen).
>> Right now I have tiles of 256x256 - which seem rather small and take 
>> some time to load.
>>     
>
> I would try to understand why they take some time to load. Are you using
> CGI mode? (Don't.) Are you not-precaching as much as you should? Are you
> using metatiles? Are you not using metatiles? etc.
>
> Also, some description of 'some time' -- hundreds of milliseconds, seconds,
> dozens of seconds -- would probably also be appropriate.
>
>   
>> What tile sizes do you use?
>>     
>
> 256x256. And so does Google Maps, which was doing this before most of us,
> and probably has a decent idea on how to make things work pretty well.
>
> -- Chris
>
>   
>> Thanks,
>>
>> Adrian
>>
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>>     
>
>   


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