[Chameleon] raster hang

Paul Spencer pagameba at magma.ca
Wed Aug 25 14:17:02 EDT 2004 

Actually, for the map image, it never gets saved to disk.  It is drawn 
directly from a php script called drawmap.php.  You can view source on 
the page and search for drawmap.php to find the URL that is actually 
called, and then paste it into the address bar to see the results directly.

Cheers,

Paul

Ken Sanderson wrote:

> Chameleon/Mapserver puts the image rendered in your mapserver temp
> folder.
> 
> Ken
> 
> -----Original Message-----
> From: chameleon-bounces at lists.maptools.org
> [mailto:chameleon-bounces at lists.maptools.org] On Behalf Of Ken-ichi
> Sent: August 25, 2004 11:42 AM
> To: Chameleon at lists.maptools.org
> Subject: Re: [Chameleon] raster hang
> 
> 
> 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
>>>>
>>>>
>>>>_______________________________________________
>>>>Chameleon mailing list
>>>>Chameleon at lists.maptools.org <mailto:Chameleon at lists.maptools.org>
>>>>http://lists.maptools.org/mailman/listinfo/chameleon
>>>
>>>
>> 
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>>
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-- 
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|Paul Spencer                           pspencer at dmsolutions.ca   |
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|Applications & Software Development                              |
|DM Solutions Group Inc                 http://www.dmsolutions.ca/|
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