The problem definately seems related to concurrency.
Load benching using 1 concurrent requests: 0 fails.
Load benching using 2 concurrent requests: +- 30% fails
more concurrent = more fails.
The failed seem to return with HTTP 500.
Running a shp2img during this time, still returns a good image.
http://trac.osgeo.org/mapserver/ticket/3099 might be related. I don't
know how fastcgi in lighty works, but mapserver in fastcgi definitely
does not play nicely with fastcgi implementations that don't expect
child processes to ever exit().
As Stpehen pointed out, I'd try with apache/fastcgi , if
Hi,
Maybe my experience is somehow related. I have just been seeding GeoWebCache
from our Mapserver this week and using more than two threads with Apache
fast-cgi proved to be very unreliable. Some of the GWC threads were dying soon
with message:
ERROR [seed.MTSeeder] - Unexpected response
Have you built mapserver with threads? If so disable this and see if the
problem goes away.
HTTP 500 probably means that your process is getting a SIGV. Also unless
you are using a database connection, using fastcgi is not going to give
you a huge benefit because of the way mapserver works.
Thanks for your comments. I'll try switching to CGI.
My current config is setup like this:
MapServer version 5.6.5 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP
OUTPUT=SWF OUTPUT=SVG SUPPORTS=PROJ SUPPORTS=AGG SUPPORTS=FREETYPE
SUPPORTS=ICONV SUPPORTS=FRIBIDI SUPPORTS=WMS_SERVER
Hi all,
I'm getting a lot of
27098 x 20 0 000 Z1 0.0 0:00.03 mapserv defunct
27104 x 20 0 000 Z1 0.0 0:00.03 mapserv defunct
while load testing mapserver. Is there any way I can go about checking out
why this is happening? Especially when doing
Here is an explanation of defunct processes:
http://www.webmasterworld.com/forum40/1032.htm
I'm sure there are others. So since you are running fastcgi, it is the
responsibility of the fastcgi parent process to clean up dead child
processes. It is likely that it is busy because you are doing
Well, the problem is that the requests are not always served.
During load testing, say about 10 concurrent requests I also load the map.
But there are randomly tiles that are never loaded. I thought this would be
related to the defunct processes, but that is not a certainty.
My setup is lighttpd
Wim,
I'm not sure I have any magic bullet for this problem, because I'm not
sure what is causing it. If this was my project, I would tackle it like
this:
1. alert people we have a problem that might impact the release date if
you have not already done that
2. divide the problem to try and
