[mapserver-users] Java MapScript and Tomcat6 Hanging

[Gilbertson, Paul]

Umberto,

Absolute lock up. Process is running, but never responds to requests. Tomcat creates threads for new requests, and accepts them, they just never return data. Tomcat/JVM never crashes.

The synchronized keyword was an attempt to fix this, symptoms are the same with or without it.

Regards,
Paul Gilbertson


> -----Original Message-----
> From: Umberto Nicoletti [mailto:umberto.nicoletti at gmail.com]
> Sent: 22 July 2010 15:04
> To: Gilbertson, Paul
> Cc: mapserver-users at lists.osgeo.org
> Subject: Re: [mapserver-users] Java MapScript and Tomcat6 Hanging
> 
> 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
> >
> >
> >
> > --
> > This message (and any attachments) is for the recipient only. NERC
> > is subject to the Freedom of Information Act 2000 and the contents
> > of this email and any reply you make may be disclosed by NERC unless
> > it is exempt from release under the Act. Any material supplied to
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> >
> > _______________________________________________
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> > mapserver-users at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/mapserver-users
> >

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