imageI’ve previously written about using PyISAPie to run Python under IIS – this allows Python scripts to run faster than using CGI. Rather than starting up the Python interpreter each time a request is made to the web server, PyISAPIe starts the interpreter once and only needs to run the script at each request.

TileCache provides a Python-based WMS-C/TMS server – this is allows you create a local disk-based cache of any WMS server (in my case MapServer), and then connect to it through a WMS-C client such as OpenLayers. Using a cache means that rather than have MapServer create an image for every single request for a tile, the first time a tile is requested the image is saved in a folder on the server. On all subsequent requests for the same data TileCache can retrieve this file without needing MapServer. Performance increase is incredible – however watch out for filling up disk space, and remember to empty the cache if you change symbology or update your data.

As mod_python is now officially dead (and has been moved in Apache’s attic), it is yet another reason if you are using Windows servers to run everything through IIS rather than the rather clumsy Apache on Windows. Why pay for Windows, and then install a web server port, thereby losing all the tools, security, and utilities within Windows to manage and administer the web server?

The aim of this post is to describe the set up of TileCache, running through IIS. Continue reading »

I’m trying (and having) to start using Python more and more due to its ubiquity in the OpenSource GIS world. There are a number of add-ons and libraries for MapServer that require Python to function properly and/or quickly. It is also widely used for scripting both MapServer objects and for raster manipulation using GDAL. I initially set up Python under Apache to run the Tilecache tile server.

According to the ModPython site – “Python will run many times faster than traditional CGI and will have access to advanced features such as ability to retain database connections.”

Mod_python is an Apache module that embeds the Python interpreter within the server, and can be downloaded from their site. There are versions for both Unix and Windows, which makes it ideal for MapServer for Windows (MS4W). Ironically after saying that using Python for web applications is many times faster than CGI, the ModPython download page uses CGI..

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