[mapserver-users] Java MapScript and Tomcat6 Hanging

[Umberto Nicoletti]

Hi Paul,
please define hang: is it a crash or simply a momentary stall?

In the case it is the latter I see the synchronized keyword in the
definition of the doLogic method and by looking at the code you have
posted it seems superflous, but there might be some other code that
you didn't post that makes it necessary. Anyway I would start looking
there.

HTH,
Umberto

On Wed, Jul 21, 2010 at 4:41 PM, Gilbertson, Paul <paulbe at ceh.ac.uk> wrote:
> Good folks,
>
> I am somewhat new to MapServer and MapScript, and I'm trying to do a few experiments with Java Mapscript in order to scope out MapServer's feasibility for a large project.
>
> I've downloaded and installed MS4W 3.0 beta 11, and Netbeans 6.9 with Tomcat 6.0.29 in order to test out Java Mapscript. I created a most basic servlet to serve up simple map tiles, and it works for serial requests. When I try to serve two requests at the same time Tomcat hangs hard.
>
> My map file and Java classes are below:
>
> MAP
>  IMAGETYPE      PNG24
>  NAME           "nbndemo"
>  STATUS         ON
>  EXTENT         -12.5 12.5 700000 1300012.5
>  SIZE           800 800
>  IMAGECOLOR     226 245 255
>  CONFIG         "MS_ERRORFILE" "/ms4w/apps/nbndemo/error.txt"
>  DEBUG          5
>
>  PROJECTION
>    "init=epsg:27700"
>  END
>
>  LAYER
>    NAME         os250k
>    STATUS       ON
>    TILEINDEX    "/OSRasterTiles/os_250k/os250k_tindex_srs.shp"
>    TILEITEM     "Location"
>    TYPE         RASTER
>    OFFSITE      71 74 65
>
>    PROJECTION
>      "init=epsg:27700"
>    END
>    EXTENT         -12.5 12.5 700000 1300012.5
>  END
> END
>
> public class SPRewriter {
>    public synchronized void doLogic(HttpServletRequest request, HttpServletResponse response) throws Exception
>    {
>        ServletOutputStream out = response.getOutputStream();
>        edu.umn.gis.mapscript.mapObj mo = new mapObj("/ms4w/apps/nbndemo/mapfiles/test.map");
>
>        imageObj image = mo.draw();
>        response.setContentType(image.getFormat().getMimetype());
>        out.write(image.getBytes());
>        image.delete();
>        mo.delete();
>    }
> }
>
>    protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
>        try {
>            SPRewriter spr = new SPRewriter();
>            spr.doLogic(request, response);
>        }  catch (Exception e) {
>            e.printStackTrace();
>        }
>    }
>
> Any thoughts why this would hang the moment I try to run parallel requests?
>
> Regards,
> Paul Gilbertson
>
>
>
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