[mapserver-users] Runaway process and other wierdness

[Daniel Morissette]

Tim, Bruno,

I also encountered similar runaway process problems with the Perl
MapScript recently but never found the root of the problem.  Since you
guys also get this with PHP, then I would I suspect that MapServer (the
core) may do something that confuses multithread environments (Perl or
PHP modules)... but that's just a guess... I'm really not sure about
that.

I've filed a bug about this in bugzilla and we should continue the
discussion and investigation of this bug there:
  http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=66

About the random map/scalebar problem, it may well be a different issue,
either related to the way the "maybe-not-so-unique" image filenames are
built by the PHP module, to something being done wrong in the PHP
module, or to some static variables (???) somewhere in MapServer that
would screw things up in multithread environments.  So I filed this as a
separate bug, and the same way we should continue the
discussion/investigation there:
  http://mapserver.gis.umn.edu/bugs/show_bug.cgi?id=67

Bruno, can you please confirm that you get this with PHP4 as an apache
module?

I'll see if I can reproduce the problems here, but if you can provide
sample scripts that reproduce them then that would help a lot.

-- 
------------------------------------------------------------
 Daniel Morissette               morissette at dmsolutions.ca
 DM Solutions Group              http://www.dmsolutions.ca/
------------------------------------------------------------
  Don't put for tomorrow what you can do today, because if 
      you enjoy it today you can do it again tomorrow.


Bruno Gendron wrote:
> 
> Hi Tim, hello everyone,
> 
> I began having the same exact problems recently
> (except from the scalebar bug), with ms3.5 (not cvs)
> on Mandrake 8, Apache 1.3.X, php 4.0.5 and
> php-mapscript. I'm not using the CGI version of
> MapServer, only php-mapscript.
> 
> >From my experiments, if php encounters any error while
> a mapscript session is in progress (in my case, my php
> script had a small warning, not fatal, error that was
> catched by an error management routine), the http
> thread does not terminate properly, leading in a
> thread "leak". After I solved this error, the leak
> ALMOST disappeared, although i cannot certify that
> this was only a coding issue on my behalf. Could it be
> a "keep-alive" problem with php or apache?
> 
> Like you, I also get random map images from previous
> requests appearing in my browser: even worse, other
> users of the app sometimes get map images from each
> other's requests!
> 
> 2 possible explanations:
> 
> - Apache gets mixed-up with it's connections, sending
> data on wrong connections (could it be possible!!!),
> 
> - or the map image filename created by Mapserver (in
> my case php-mapscript) is not really UNIQUE filenames,
> so one image gets could get cached by the browser and
> displayed back later if the map image filename is the
> same...
> 
> I will, this morning, modify my php scripts to
> generate, from within php, a randomly generated
> kind-of-unique filename to see if it solves anything.
> I will also modify my app to send a bogus
> randomly-generated http-post parameter to trick the
> browser cache, and I will get back with my results...
> 
> --
> Bruno Gendron
> 
>  --- Tim Sutton <sutton_t at giug.net> a écrit : > Hi
> >
> > I am having a problem with mapserver (redhat 7.1 +
> > apache module + php)
> > where the server http threads for mapserver requests
> > run away and hog
> > all the processor time. This has been happening
> > using the cvs version
> > and ms3.4. This has only suddenly started happeining
> > so I am not sure
> > why? Any Ideas?
> >
> > Also, I have another problem: If I browse around on
> > one mapserver app
> > on my server, then change the url in the same
> > browser session to
> > another mapserver app, I get images from the first
> > app seemingly
> > randomly dumped into the second. Has anyone
> > encountered this? Another
> > wierd thing it does is when I am zooming in to the
> > map, a very
> > enlarged version of the scalebar suddenly gets
> > rendered in the
> > mapwindow??
> >
> > Any thoughts on how to resolve these problems will
> > be greatly
> > appreciated.
> >
> > Regards
> >
> > Tim Sutton
> >
> 
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