We have a custom web application that uses SQL Server 2008 (10.50.1600). It's worked fine for years, but lately web pages that return data "instantaneously" have begun showing the "endless swirly blue thing" in IE. Something is causing queries to run slower, lock, contend or something else. Doesn't seem to be deadlocking, as I am not seeing deadlock errors at the user level, which I have (very rarely) seen (and know they will trigger a specific error).

If users close out of IE completely and go back in, they usually are able to do the previous work without this hanging behavior (well, until such time as the hang happens again).

How would you begin to diagnose the source of this issue?

  • How do you know it's latency on the database side? Have you traced watched the HTTP request(s)? Apr 3 '12 at 18:51
  • Good point. How would you monitor that? I guess I need to keep a monitor on baseline behavior both in the DB and in IIS, and then check for anything that spikes out of norm...
    – alphadogg
    Apr 3 '12 at 18:53
  • On the client side, you can use the FireBug plugin for Firefox. It's a great tool that allows you to see the request, time spent, etc. It very well may be getting held up at the database. When this happens you need to look at the user connections to see their wait type and if they're blocked. Apr 3 '12 at 18:56
  • BTW, while one user is locked up in blue swirlies, other users are using the app just fine.
    – alphadogg
    Apr 3 '12 at 18:57

I would check at logs, 1) IIS Logs 2) Windows Logs 3) SQL Server Logs

I think logs usually gives away a hint in case of any issue.


Use SQL Profiler on the SQL Server side to see the commands running on the SQL Server side. Download sp_whoisactive and put it on your SQL Server and use that to see if there are any commands which are locking, blocking, being blocked, etc.

Use WireShark and FireBug to see the calls from the client to the server.

  • Sorry for the one month reply delay, but the issue is intermittent and user-specific. Out of 50 users, maybe one or two see this issue about 4-5 times a day. Is there some sort of longer-term, centralized monitoring I could do?
    – alphadogg
    May 3 '12 at 18:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.