On Tue, Sep 6, 2011 at 7:40 AM, Ziegler Stefan <[email protected]> wrote: > Hi > > We are serving some aerial images with the ImagePyramid plugin. Tiling was > done with gdal_retile: 2000x2000px, Geotiff with LZW compression and alpha > channel. Performance is really nice but from time to time it takes 10 or more > seconds to deliver the wms request. This happens only when Geoserver has to > use the 0 level tiles where we have 11'144 tiles. Can the amount of tiles in > one single directory be a issue? CPU load is not increasing during the > request.
Yes, it can be an issue. The pyramid is just a stacked set of mosaics, so the pyramid just delegates to the mosaic readers. Each mosaic is cached in a soft cache, meaning it can be garbage collected and in need of being reloaded. On reload the mosaic will take the shapefile index and load it in memory, which in the case of a large mosaic migth take time. Try adding: Caching=false in each and every property file of the mosaics, this should make the mosaic not load the tile index in memory, but query on disk every time, which should prevent the 10 seconds delay (it will of course have a toll on each request, querying on disk is slower than hitting the in memory index). There is also the issue of having to open all those little files, in general it's bad practice to slice information in a ton of tiny files. Pyramid generated with tools like gdal_retile, using the default settings, might be useful for tile caches but in general it's much better to setup the mosaics with (very) large files and overviews, and keep low both the number of levels and the number of files. Cheers Andrea -- ------------------------------------------------------- Ing. Andrea Aime GeoSolutions S.A.S. Tech lead Via Poggio alle Viti 1187 55054 Massarosa (LU) Italy phone: +39 0584 962313 fax: +39 0584 962313 http://www.geo-solutions.it http://geo-solutions.blogspot.com/ http://www.youtube.com/user/GeoSolutionsIT http://www.linkedin.com/in/andreaaime http://twitter.com/geowolf ------------------------------------------------------- ------------------------------------------------------------------------------ Special Offer -- Download ArcSight Logger for FREE! Finally, a world-class log management solution at an even better price-free! And you'll get a free "Love Thy Logs" t-shirt when you download Logger. Secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsisghtdev2dev _______________________________________________ Geoserver-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geoserver-users
