|Subject:||500 error - out-of-memory exception|
|Posted by:||Griff (griffithsj_5…@hotmail.com)|
|Date:||Tue, 7 Jul 2009|
We have an IIS server that successfully runs a classic ASP web site
for many days and then all of a sudden the every ASP page responds
with a 500 error message.
Looking through the web logs, we find out of memory exceptions.
However, gone through all the code and it's not obvious where there
could be a memory leak....
Anyhow, decided to monitor the memory usage at the point of iis
dying. There is a Window's API function GetProcessMemoryInfo which
returns the process' memory usage.
I logged the WorkingSetSize, PeakWorkingSetSize, PageFileUsage and
Most of the time whilst the server was healthy, I got the following
example values (all in MB):
PageFileUsage = 880
WorkingSetSize = 882
PeakPageFileUsage = 917
PeakWorkingSetSize = 918
So, these are all quite high values, but the server is a Win2000
server with 4GB of RAM (so IIS should have about 2GB to play with if I
understand this correctly).
However, at the time of the crash I got the following values:
PageFileUsage = 842
WorkingSetSize = 747
PeakPageFileUsage = 899
PeakWorkingSetSize = 904
So....at the time IIS fell over, the PageFileUsage was GREATER than
the WorkingSetSize. Not sure how this can be....
Any explanation would be most welcome.
Thanks in advance