On 3/31/2011 2:21 AM, Jon Blower wrote:
Hi Lin, all, Memory issues in Java are often mysterious because the garbage-collection is hidden from view. But I can't see any reason why the request below (which is small) should cause memory problems. The size of the dataset doesn't matter for a GetMap request, and the size of the image doesn't matter much (it matters a bit, but should be trivial for a 100x100 image). So I don't really know what's going on here. If you start from a fresh reboot and make the same GetMap request, do you consistently get the error? Or only after a period of use?
To aid in diagnosing memory problems, you can add "-verbose:gc" to JAVA_OPTS= in your [tomcat]/bin/startup.sh or setenv.sh file.
Jon -----Original Message----- Hi John, Thanks for the information. My large datasets will eventually be hosted on a 64bit JVM. At the moment, I'm testing a 1.3GB dataset with -Xmx1536m on a dev machine. The following WMS request results in HTTP Status 500 - Internal Server Error (java.lang.OutOfMemoryError: Java heap space): http://localhost:8090/thredds/wms/aggregated/magmap_V5_2010_s.nc?service=WMS&version=1.3.0&request=GetMap&Layers=magmap_V5_2010&CRS=EPSG:4326&BBOX=152,-39,154,-37&width=100&height=100&Styles=BOXFILL/occam_pastel-30&format=image/jpeg The dataset has an bounding box: <westBoundLongitude>112.50461544244448</westBoundLongitude> <eastBoundLongitude>154.66376524558447</eastBoundLongitude> <southBoundLatitude>-39.560232620003625</southBoundLatitude> <northBoundLatitude>-35.19773436500001</northBoundLatitude> I guess the request is faily small (BBOX=152,-39,154,-37) . I In addtion, the NetCDFSubsetService works fine for the same dataset with the same amount of memory. I'm wondering if in general case, the maximum heap is determined by the dataset size for Thredds WMS service, and if there is an configuration option to limit the WMS request size. Regards and thanks, Lin ________________________________ From: thredds-bounces@xxxxxxxxxxxxxxxx [mailto:thredds-bounces@xxxxxxxxxxxxxxxx] On Behalf Of John Caron Sent: Thursday, 31 March 2011 5:21 AM To: thredds@xxxxxxxxxxxxxxxx Subject: Re: [thredds] Large aggregated datasets, WMS memory issue Hi Lin: It doesnt (usually) matter how big the dataset is, just how big the request is. Can you send a typical WMS request that causes this problem? Do you know what size of data you are requesting? What file format? -Xmx1536m is around the max for 32 bit JVMs. I strongly advise you to use a 64bit JVM with more like 4 Gbyte heap. John _______________________________________________ thredds mailing list thredds@xxxxxxxxxxxxxxxx For list information or to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/
-- Sincerely, Bob Simons IT Specialist Environmental Research Division NOAA Southwest Fisheries Science Center 1352 Lighthouse Ave Pacific Grove, CA 93950-2079 Phone: (831)658-3205 Fax: (831)648-8440 Email: bob.simons@xxxxxxxx The contents of this message are mine personally and do not necessarily reflect any position of the Government or the National Oceanic and Atmospheric Administration. <>< <>< <>< <>< <>< <>< <>< <>< <><