I didn't do anything with error messages, because it's a production system
and I wouldn't want users seeing complex error messages; and also I am not
sure anyone is really seeing error screens. Users are definitely seeing the
system hang up and take 45 seconds to process a page. I personally have
never seen an error screen associated with this problem. It's difficult to
reproduce, alas.
My server logs include sections like this, usually following a gap of 30-90
seconds with no log entries:
2006-04-18 20:15:38 65.90.32.22 - 64.92.223.220 80 POST /survey.asp - 200
2006-04-18 20:15:38 65.90.32.22 - 64.92.223.220 80 POST /survey.asp
|-|ASP_0147|500_Server_Error 500
2006-04-18 20:15:38 65.90.32.22 - 64.92.223.220 80 POST /survey.asp
|-|ASP_0147|500_Server_Error 500
2006-04-18 20:15:38 65.90.32.22 - 64.92.223.220 80 POST /survey.asp
|-|ASP_0147|500_Server_Error 500
2006-04-18 20:15:38 65.90.32.22 - 64.92.223.220 80 POST /survey.asp
|-|ASP_0147|500_Server_Error 500
2006-04-18 20:15:38 65.90.32.22 - 64.92.223.220 80 POST /survey.asp
|-|ASP_0147|500_Server_Error 500
2006-04-18 20:15:38 65.90.32.22 - 64.92.223.220 80 POST /survey.asp
|-|ASP_0147|500_Server_Error 500
2006-04-18 20:15:38 65.90.32.22 - 64.92.223.220 80 POST /survey.asp
|-|ASP_0147|500_Server_Error 500
That's nine entries from the same client in the same second, one of which
looks successful and eight being errors. The client is not really making
nine requests in one second. Maybe the user is getting impatient and hitting
submit repeatedly (since the server usually responds in a second or two), and
all the requests are being logged at the same time after the server gets
itself un-hung.
My challenge is to find out why it's hanging up.