For Windows users I have been distributing shp2tile with MS4W
(https://ms4w.com/), and in fact the last MS4W contains a rebuilt
shp2tile (and an updated Shapelib), which as Lars said is still very useful.
-jeff
On 2019-11-11 4:07 PM, lars.schylb...@blixtmail.se wrote:
Hi
I have had a similar situation as You with large national data sets in
shape format. One of the biggest improvements for me has been to split
large shape files into smaller and
then use vector tile indexes in Mapserver.
The tool shp2tile has been working well for me. Stephen Woodbridge has
written that tool. It can be found at
http://imaptools.com/download-software.html
<http://imaptools.com/download-software.html>
I think that You had to compile yourself on linux, but that was easy.
I have an example where I have automated this in a script that runs
through all shape file in a directory and splits shape files larger than
a certain size and then creates the vector tile index files.
The code snippet that is part of larger import script can be found here:
https://gist.github.com/LarsSchy/644b37ab2b1e58b48808bfb2b57d0359
The script snippet also shows the normal optimizations we do.
Hope this could give You some ideas how optimize and make Mapserver and
Mapcache run faster. I also ran into the problem with to many inodes.
That got solved by using sqlite as backend in Mapcache.
Best regards / Lars Schylberg
11 november 2019 kl. 15:42, "Travis Kirstine" <traviskirst...@gmail.com
<mailto:traviskirst...@gmail.com?to=%22Travis%20Kirstine%22%20<traviskirst...@gmail.com>>>
skrev:
I may not be unrealistic for it take mapserver to 4-6 seconds to
generate 4096px image depending on the amount data being rendered
and the complexity of your styles / expressions / labels. If your
mapserver is able to generate a 1024x1024 in under a second that is
pretty good. Like Jukka and other suggest I would look at
translating the files to shp files with spatial indexes or postgis
tables with spatial and attribute indexes if necessary.
Preprocessing the data (simplification / prefiltering / point
thinning cluster) and using SCALETOKENs to reference different
source layers at different scales can lead to big performance boosts
at the mapserver end.
For us the biggest limiting factor has been the write blocking to
sqlite cache when seeding tiles, if you increase the number of
threads / process in mapcache seed those process will just end up
waiting to write to the cache. You can generally figure out what the
max number of processes the cache can handle by running a seed on a
test area and look at the number of tiles seeded per second, as some
point -n will have no effect which your process are just waiting to
write the cache. I would look at using this method to test sqlite vs
disk or other backends. The GeoTiff cache may be promising as it
appears to be non-blocking but experimental...
We use a riak cache with a riak leveldb backend which works well for
us but is a bit of a pain to manage as it difficult to delete
objects so it's not great for caches that need to be refreshed.
Finally you may want to test MapProxy as an alternative to MapCache
(we use both). MapProxy supports a non-blocking compact cache that
could solve your inode problem
Regards
On Fri, 8 Nov 2019 at 11:48, Sebastiano Laini
<sebastiano.la...@buchanancomputing.co.uk
<mailto:sebastiano.la...@buchanancomputing.co.uk>> wrote:
We don’t create the data, we rely on OS (ordnance survey) to
supply us the maps files and then we publish them in our service
but I assume that probably we will need to create some flow to
improve it or download it in other format that is faster.
Sebastiano Laini
Web Developer
Buchanan Computing
*From:*Fawcett, David (MNIT) [mailto:david.fawc...@state.mn.us
<mailto:david.fawc...@state.mn.us>]
*Sent:* 08 November 2019 16:41
*To:* Sebastiano Laini <sebastiano.la...@buchanancomputing.co.uk
<mailto:sebastiano.la...@buchanancomputing.co.uk>>; 'Rahkonen
Jukka (MML)' <jukka.rahko...@maanmittauslaitos.fi
<mailto:jukka.rahko...@maanmittauslaitos.fi>>;
'mapserver-users@lists.osgeo.org
<mailto:mapserver-users@lists.osgeo.org>'
<mapserver-users@lists.osgeo.org
<mailto:mapserver-users@lists.osgeo.org>>
*Subject:* RE: mapcache seed speed optimization
For data formats that are slower to read, would it add fit your
workflow to convert it to different data format before creating
the tiles?
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