ASP & IIS - memory just drains away....
Posted on 2000-03-07
I have a busy site running IIS4 & using ASP/ADO (quite a bit....).
Over a period of time (4-6 hours) the memory just leaks away - I have reduced my usage of Session variables to an absolute minimum and the site runs faster - but the memory seems to leak away even faster.
It looks as if IIS doesn't garbage collect it's ASP space quickly enough, and the load on memory just builds up more quickly than it is being cleared out (see below - if left alone it DOES eventually clear out).
Running in separate memory space just seems to make it worse.
Response times are OK (20 threads) until memory gets in short supply, then it falls apart quickly.
I have run the site in isolation with test sessions only, and if I let the site go quiescent, the memory comes back after about 50 minutes (20 minutes session timeout + 30 minutes) - this is quite consistent.
If I just drive the site at 'live' speed then I get the same problem. Extra memory on the web server just delays the inevitable.
The question is : How do I fix this...
1. Using session variables AT ALL?
2. A tuning issue for IIS (e.g. forcing garbage collect)?
3. More webservers to spread the load?
4. Getting the server to detect the situation and auto-reboot (how?)
5. Something else........
Any advice much appreciated.