Slow ASP Pages on IIS6 / Windows 2003

[Akerlund]

User clicks a link that displays a customer card and financial stats (has a
lot of database calls). Every 5 times the user clicks the same page/link it
takes about 30 seconds (normal response time is <1 second) to display. Then
you can click 4 times with a normal response time and the 5th the repsone
time it is 30 seconds again. The page has exactly the same parameters every
time but there seem to occur some "locking" that stops the action every 5
calls but I can not understand what this is. For other pages this could be
every three pages or every ten pages depends omn the amount of database calls.

Info:
The exactly same page and database works fine on IIS5 with consistently <1s
response times no matter how many times the page is displayed in row.

ASP application moved from IIS5/2000 to IIS6/2003. Database SQL2000 on
different server (not changed at move).

Database calls use adodb and are closed (.close() ) when used. Database
connections is set to Nothing after use.

Tracing the the database calls on the sql server shows that the calls stop
for about 30s (last command audit logout) and then commences normally.

Any suggestions on how to remedy this situation so that the 30s "hickups"
would disappear?

 

[Akerlund]

Some additional info:
If I request the page 4 times and then wait more than 30 seconds before I
request it again I can request it 4 times with 1s response time, then wait 30
seconds and request 4 times again etc all with 1s response times. Something
seems to be recycling or released but what?

Running II6 in IIS 5 isolation mode have the same problems. Using IP or
hosts file for db connection have the same problems.

 

[GeorgeScott]

Try combining some of those querys into one by joining the tables and

a) If you only want one record use TOP 1 (select TOP 1 id,first,last
from table where ID = 5)

b) Make sure your tables are indexed, if you use say userID =1 and
CompanyID = 0 in your sql query then be sure that there is an index
for Record & Company together so it won't have to scan the rows so
much.

c) Use 0,1:
sSQL = Select TOP 1 ID,First,Last from Table where CompanyID =0 and
userID = 1
rs.open sSQL, Conn, 0, 1

Thanks

George Scott
http://www.officezilla.com/whatisit.asp

 

[Akerlund]

Hi George,
thank you for your answer, but I fail to understand how that would affect
that the page works fine on a machine with IIS5 (we are connecting to the
same database from both the machine with IIS5 and the machine with IIS6).

We are using indexes on join fields.

 

[Anthony Jones]

Hi George,
thank you for your answer, but I fail to understand how that would affect
that the page works fine on a machine with IIS5 (we are connecting to the
same database from both the machine with IIS5 and the machine with IIS6).

We are using indexes on join fields.

Have checked the event logs on both the IIS6 and SQL2000 server machines?

 

[Akerlund]

Event logs checked on both machines (iis/db) and I can see no entries
connected to the problems, there are no events at all during the "test" runs

 

[Akerlund]

Did a new install of a web server (2000/IIS5 ) and the error could be
repeated so now I am thinking that this is a firewall problem (firewall
changed from Cisco Pix to Microsoft ISA).

 

[Akerlund]

Problem solved.

"ISA Server limits the number of connections at any given time. You can
configure the limit, specifying a maximum number of concurrent connections."

We raised the limit from 1000 to 2000 and now the application runs smoothly.

More info can be found here:

http://www.microsoft.com/technet/isa/2004/plan/securityhardeningguide.mspx