Blank images with mapscript in redhat enterprise 4

[Daniel Morissette]

Please do not cross-post questions to the -users and -dev list. I have 
intentionally sent this response only to the -users list since that's 
where it belongs.

A few things to try/check:

1- You write that the application crashes? Do you mean that you see 
segmentation fault messages in the error_log? If not then what are the 
symptoms of the "crash"? You also write that you get blank images 
randomly... so is the problem that you get blank images, or that the 
requests crash/abort and return only partial responses?

2- Is it possible that your RHE system is running PHP as an Apache 
module and not PHP as a CGI? Can you please confirm that?

3- I'd recommend that your use MapServer 4.10 for your tests, it 
contains a fix for bug 1322 that might be related to your problem

4- In general when you get intermittent seg faults they are caused by 
conflicting libraries used by one of Apache, PHP or MapServer/MapScript. 
For instance if your PHP includes the GD extension and uses PHP's 
built-in version of GD then that might be a source of conflicts with the 
system GD used by MapScript. You could try rebuilding PHP without the GD 
extension, or if you need the GD extension then use the system GD, i.e. 
the same GD that is used by MapServer and PHP MapScript.


Daniel


José Vicente Higon wrote:
> Hello,
> I have a problem with an application developped with mapscript, I recive 
> empty images randomly. Initially, the application was developped in 
> windows and it worked fine, when we put it in linux it began to fail 
> (readhat enterprise 4 Nahant). Now, we have installed these versions:
> 
> httpd-2.0.55
> php-5.0.5
> postgres-8.0.3
> mapserver-4.8.4
> gdal-1.3.2
> gd-2.0.33
> ....
> 
> I've tried with newer and older versions of mapsrver, gd, php (php4 too) 
> , ... but it continues failing. I'm desperate !!
> All layers are in debug mode, however when the appplication crashes, the 
> output log (error_log apache's) stops be writed and any messages can 
> give me any clue.
> 
> Can someone help me?
> 
> Thanks in advance
> 


-- 
Daniel Morissette
http://www.mapgears.com/