Hello, Le Mon, 16 Apr 2012 21:39:50 +0200, David MENTRE <[email protected]> a écrit :
> I am glad to see that your are making progress in locating this > annoying bug. Locating it is half fixing it. ;-) I had a discussion with Dane Springmeyer on the #mapnik IRC channel, and he said that the behaviour is expected: Mapnik keeps the shape files opened as a cache. We need to disable this at compile time by setting the SHAPE_MEMORY_MAPPED_FILE=False value when calling the configure script. > I think this option is the most tolerant to this error and other > similar errors that would certainly occur in the future. While it > might not be the cleanest from an idealistic point of view, it uses > the isolation features of our underlying OS and ensures that > everything is properly cleaned-up. In fact, I thought it was the way > the rendering pipeline was implemented. :-) > > Regarding performance, I think (but not measured) that the overhead of > forking a process is negligible compared to other overheads we have, > like database queries. I agree that we should use one process for each rendering. It guarantees the isolation between renderings, and the cost of the fork/exec compared to the rendering itself is negligible. Maxime told me today that he would work tomorrow on implementing this. Regards, Thomas -- Thomas Petazzoni http://thomas.enix.org MapOSMatic http://www.maposmatic.org Logiciels Libres à Toulouse http://www.toulibre.org Embedded Linux http://www.free-electrons.com
