Scenario: There were four websites on the load balancer. Two nodes websites were working fine and the websites on the other two nodes were down. The error was Internal server error 500.19.
These are the steps I followed to troubleshoot the issue. Hope these steps may help you!!! :)
-> check the other nodes websites are working.
-> check the log files for error(cntrl end+scroll to extreme right)
->in the website root folder you can see a file called ping.html.Type in the website name <wwwstag.test.com/ping.html
if the page is not being displayed then the request is not going to the server
Refer this----->http://www.dondraper.com/2011/01/500-internal-server-error-from-iis-7-5-on-windows-2008-r2/
TROUBLESHOOTING:
1) Checked if the websites on all other nodes are working. Websites on node1 and node2 were not working and on node3 and node4 were working fine.
2)Checked the DNS and host header details and everything looked good.
3) Checked the log files and event logs and coulnt find any errors.
4) Changed the ASP details.....enabled the "Detailed ASP error" and couldnt find the error.
5)Tried replacing the web.config file from the working node and it did not work.
6)Tried mapping to the third node content path and detailed error message was displayed.
7)changed the security permissions, enabled the error tracing detail and checked...but couldnt find out the exact error.
8)COmpared the Modules and application pool setting with the working node and not working node...and all the settings were same.
9)Created a Test website with the same url and with the test html page and it was giving the same error.
10)Finally enabled the 32 bit application support in the application pool properities and that resolved the issue.
CONCLUSION:
The 32-bit application was enabled because the website was configured with 32 bit modules and handlers that require 32 bit compatibility.