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Hello Christopher,<br>
<br>
I've set it up with mod_python and it absolutely flies! :) Thanks again
for the help.<br>
<br>
I would recommend you (or somebody who has edit rights to the
documentation) add these tips on the main documentation page:<br>
* cgi has relatively low performance (~10 queries per second)<br>
* when installing under mod_python, don't copy your tilecache
instalation under cgi-bin, because it's used as Script-Alias and causes
problems. Also, don't worry if you can't find the file tilecache.py -
the apache configuration must point to the correct directory (which
contain tilecache.cgi, tilecache.fcgi...) and it will work. See
<a class="moz-txt-link-freetext" href="http://openlayers.org/pipermail/tilecache/2007-December/000661.html">http://openlayers.org/pipermail/tilecache/2007-December/000661.html</a> for
details.<br>
<br>
Thanks,<br>
Adrian<br>
<br>
Christopher Schmidt wrote:
<blockquote cite="mid:20091020142740.GG4436@metacarta.com" type="cite">
<pre wrap="">On Tue, Oct 20, 2009 at 04:25:01PM +0300, Adrian Popa wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Thank you,
I'll try with mod_python.
Another small question - is there any notable speed difference between
using tilecache (let's say through mod_python) to serve some pre-cached
tiles and using OpenLayers.Layer.Tilecache to serve the same pre-cached
tiles?
</pre>
</blockquote>
<pre wrap=""><!---->
Some. The key difference is that serving pre-cache tiles can be done on much
lower resource webservers. mod_python can get bulky, but Layer.TC can
read from a minimal webserver like lighthttpd, etc. that tileCache itself
wouldn't want to be run on.
</pre>
<blockquote type="cite">
<pre wrap="">I'm thinking if I should pre-cache my whole map and use Layer.Tilecache
or if I can get away by using tilecache.py...
</pre>
</blockquote>
<pre wrap=""><!---->
You probably don't need to pre-cache your whole map. You will see a
tremendous speedup switching to mod_python.
</pre>
<blockquote type="cite">
<pre wrap="">Has anyone done any benchmarks for these methods? If the speed
difference isn't that great, I wouldn't sacrifice the disk space...
</pre>
</blockquote>
<pre wrap=""><!---->
The speed difference is not quite nonexistent, but is negligable for
anything but the most demanding use case (hundreds of users, etc.)
</pre>
<blockquote type="cite">
<pre wrap="">Thank you.
Christopher Schmidt wrote:
</pre>
<blockquote type="cite">
<pre wrap="">On Tue, Oct 20, 2009 at 09:43:35AM +0300, Adrian Popa wrote:
</pre>
<blockquote type="cite">
<pre wrap="">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...
</pre>
</blockquote>
<pre wrap="">Okay, using CGI is the problem. You can only get about 10 tiles/second
with CGI, compared to hundreds with WSGI, mod_python, etc. So I recommend
setting up mod_python or some other persistant server side process for
serving the tiles, rathere than using CGI, which is much slower.
</pre>
<blockquote type="cite">
<pre wrap="">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...
</pre>
</blockquote>
<pre wrap="">
</pre>
<blockquote type="cite">
<pre wrap="">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:
</pre>
<blockquote type="cite">
<pre wrap="">On Mon, Oct 19, 2009 at 02:30:44PM +0300, Adrian Popa wrote:
</pre>
<blockquote type="cite">
<pre wrap="">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.
</pre>
</blockquote>
<pre wrap="">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.
</pre>
<blockquote type="cite">
<pre wrap="">What tile sizes do you use?
</pre>
</blockquote>
<pre wrap="">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
</pre>
<blockquote type="cite">
<pre wrap="">Thanks,
Adrian
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</pre>
</blockquote>
<pre wrap="">
</pre>
</blockquote>
<pre wrap="">
</pre>
</blockquote>
<pre wrap="">
</pre>
</blockquote>
</blockquote>
<pre wrap=""><!---->
</pre>
</blockquote>
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