PHP MapScript hangs or performance degradation

[Mark Alexander]

I am seeing very similar symptoms.  I am running C# mapscript, and I've
wrapped it in a .Net web service.  The web service will periodically peg
the processor at 100%.  Appears to be in an endless loop.  We opened a
priority support ticket with Microsoft.  They read a dump and determined
the issue is inside the mapscript dll.  We just prepared a debug build, did
a dump, and Microsoft is going to analyze the problem.

Curiously, we are using shapefiles too.  We tried to verify them, and one
had an error opening in ArcInfo.  We replaced it with an uncorrupted copy,
and the problem now occurs far less frequently.  Based on that, it is my
belief that our problem has to do with map server or mapscript having some
problem with handling certain shapefiles, and that it goes into an endless
loop.  For us, the problem would also 'correct itself' but that is simply
because the process running the code would recycle.

SO--we are probably going to move away from shaepfiles to ArcSDE.  I am not
sure this will fix the problem--but it might help.  We are also going to
find out what Microsoft says.  I think they'll be able to pinpoint the code
that is looping.

Feel free to email me if you want to learn the result in a few days.