Hello IIS forum!
Our website has been working flawlessly until recently - we noticed that some pages began to intermittently load slowly, hanging for somewhere between 10-30 seconds, sometimes loading successfully after a considerable wait, but in many cases leading the application in the app pool to hang for a long time, and sometimes requiring a manual restart of IIS. Even restarting IIS takes a long time when it's hanging.
The website is several years old and coded in classic ASP/VB - the pages seemingly causing the bother are fairly heavy ones in regard to sever side code with lots of recordsets etc, but have NEVER caused any problems until the last couple of weeks or so.
The website app runs in 32bit compatibility mode set in the IIS apppool (We use 32bit mode as we're connecting to a 32bit mysql database on another server via win-mysql 32bit ODBC connector)
Where things stand currently.
- No changes have been made to our classic ASP application source code.
- No applications were installed recently on the server.
- No changes made to the website conf/app in IIS
- Disk space looks fine. Disk check OK. CPU looks OK.
What I have done so far without success:
- Deleted website & app in IIS and recreated.
- Isolated website in IIS - turned all other websites and apps off.
- Uninstalled windows updates < 80 days (I have since reinstalled after discovering it made no difference)
- Performed a system restore of server state/config < 75 days
- Replaced hard disks and rebuilt array
- Uninstalled & reinstalled classic ASP component via server management console.
Despite the actions taken above I can still recreate the problem by simply making multiple requests to one of the dynamic pages. It may take a couple of minutes but I can force its hand soon enough.
Things I've also tried:
- Setup a failed trace request in IIS for the app and set the trigger to 20 seconds. I have examined some of the large xml files outputted in verbose but can't see any actual 'errors' or 'warnings'. Just some repeated references to certain parts of the source code. Just to reiterate. - this source code has been working perfectly for some years.
- Tried older, known working versions of the source code just to make sure we hadn't accidentally changed anything.
- Reinstalled 32bit mysql 5.1 driver ODBC (longshot)
-----------------
Please can someone help. I've been on this problem for 72 hours straight and have come to the end of the line for my knowledge and I don't know what else to do apart from ask for help.
This is a live server and I need to resolve this quickly (if I don't want to lose my job lol) - I'd also be willing to reward an IIS engineer to look at this in more detail to help me find a resolution.
Cheers,
Matt
#Hardware/Software
Windows Server 2012 r2 with all updates.
IIS 8 + SQL SERVER