[Chameleon] raster hang

[Ken-ichi]

Interesting workaround, Jacob.  My map image is 400x450, which doesn't 
seem exorbitantly large to me.  While it does seem like this is a 
PHP-related problem, I have my doubts about blaming PHP's performance if 
the problem doesn't occur with a file of the same size but in a 
different format (i.e. the .img that seems to work ok for me).  This 
might make sense if I was using the built-in TIFF functionality as 
opposed to GDAL but I compiled MapServer without the --with-tiff, so in 
theory it should be relying on GDAL for TIFFs.  Is there any way to 
confirm this?

I was also unable to find the URL for my map image to test if it's 
getting rendered.  All I see is skins/default/images/a_pixel.gif.  How 
exactly does Chameleon render and store the map image?

Do you experience this problem in a non-Chameleon phpMapScript environment?

-Ken-ichi

Jacob Delfos wrote:

> Ken-Ichi,
>  
> It sounds a little bit like the problem I seem to have with rasters; 
> only happening every so many times, especially when there is more 
> image in view. I have it with ECW's and TIFF (45MB RGB). My map image 
> fails, and the session seems to hang, because I can't submit the page, 
> but I seem to be able to open a new session in another window without 
> much delay. I tried changing my settings in php.ini, but it had no 
> effect. I have 'patched' my problem by placing the OnError tag in the 
> mapDHTMLwidget image, invoking a function when it fails, which 
> re-loads the map image after a small delay. My diagnosis so far is 
> that something gets ahead of itself, serving the source to the client 
> browser, and the client browser requesting the image, before the image 
> has begun being rendered. You will find that the URL of your mapimage 
> is valid.
>  
> I think it happens with PHP because it's slower than, for example, 
> mapserver. What is the size of your map image. Is it larger than 
> average, by any chance?
>  
> Jacob
>  
>  
>  
> -----Original Message-----
> From: chameleon-bounces at lists.maptools.org 
> <mailto:chameleon-bounces at lists.maptools.org> 
> [mailto:chameleon-bounces at lists.maptools.org] On Behalf Of Ken-ichi
> Sent: 25 August 2004 04:07
> To: Chameleon at lists.maptools.org <mailto:Chameleon at lists.maptools.org>
> Subject: Re: [Chameleon] raster hang
>  
>
> I should also mention that this problem is probably TIFF specific.  It
> does not occur when I use an Erdas Imagine (.img) format image of the
> same area, which is also about the same file size.
>  
> -Ken-ichi
>  
> Ken-ichi wrote:
>  
> > Thanks for responding, Paul.  I've actually set my php.ini file to be
> > very lenient on resource use for other purposes, so I doubt it's that:
> >
> > max_execution_time = 60
> > max_input_time = 120
> > memory_limit = 510M
> >
> > I did a little more testing and found that this also happens with
> > non-Chameleon phpMapScript (the MapLab non-ROSA preview app), and with
> > other GeoTIFFs, but not with the mapserv CGI or the ROSA applet.  So
> > I'm guessing you were right to suspect the PHP side of things.  Any
> > more ideas, or should I take this to a more MapScript specific list?
> >
> > -Ken-ichi
> >
> > Ken-ichi wrote:
> >
> >> Hi folks.  I've started trying to add a GeoTIFF to my Chameleon app,
> >> and it really bogs it down, sometimes to a stand still.  The image
> >> I'm experimenting with is a 29mb unsigned 8bit GeoTIFF created in
> >> Erdas.  The hangs are most frequent when the tiff occupies the whole
> >> map, and when I say hang, I mean that the map just doesn't render. 
> >> The hangs also seem to generate an httpd process that takes up a lot
> >> (>20%) of my CPU activity.  The relevant portion of my map file is
> >> pretty simple:
> >>
> >> LAYER
> >>    NAME "Test Raster"
> >>    TYPE RASTER
> >>    DATA "/path/to/data.tif"
> >>    STATUS DEFAULT
> >> END
> >>
> >> I haven't specified an outputformat, except in the MAP section, where
> >> I've set it to PNG (but I've switched around and that doesn't seem to
> >> make much difference).  This problem does not seem to occur outside
> >> of Chameleon (everything works fine in MapLab's ROSA applet), and it
> >> doesn't happen every time the map is loaded  (although it inevitably
> >> happens if you refresh the map enough).
> >>
> >> Has anyone experienced this kind of behavior before?  Even better,
> >> anyone have any recommendations?
> >>
> >> -Ken-ichi
> >>
> >>
> >> _______________________________________________
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> >
> >
>  
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