I am running a DNN 3.2.2 site for a local governmental agency that gets about 165K page views a month. It is running on a beefy Windows Server 2003 box, with the database on a separate server. About once a week (give or take a day), the site suddenly stops working - visitors just get an error page saying 'The Assembly Version does not match the Database Version. Error: Could not connect to the database. SQL Server doesn't exist or access denied."   Restarting IIS without rebooting the server doesn't fix it - only rebooting the entire server that has IIS on it fixes the problem.

I can't figure out what is causing this problem. When I try to troubleshoot the problem, I fnd that the database itself is working fine - I can open it in Enterprise Manager and work with it.  The network connection between the IIS box and the db box is fine - I can ping the db server from the IIS box. The IIS server itself is performing fine - no heavy CPU loads. Other websites on that IIS server continue to run fine, as do other applications running on the server.

This seems to happen on the weekends, so I'm not usually around to monitor it to see if there is any strange behavior before it goes down. I think this week, I will reboot the server mid-week, and see if I can at least get the pattern to change so that it goes down during the week, when I will be able to monitor it more. That should also eliminate the possibility that some event that occurs only on the weekends is causing the problem - if I re-boot it mid-week, and it still goes down over the weekend, that would suggest something that happens over the weekend is the culprit.

My server people have tried to tell me it is a DNN issue, but I don't believe it is. Other than what I mention above about re-booting it mid-week, I don't know how to proceed with troubleshooting the problem. Has anyone else experienced this, or does anyone have any ideas of what I could do to figure it out?

Thanks!
Anne

1 - The site is running in the Default Application Pool, with other websites. Do you think it would be beneficial to put it in its own?

2 - I don't see any errors in the Application log on my server before my server goes down. One thing I forgot to mention above (actually I thought I had mentioned it, but I must have erased it while I was editing - argh!) , the site will respond poorly for a few hours before going down -  the user will get errors about a page or a module not being able to load, with different error messages being shown. So, in the site log, there are tons of Page Errors and Module Errors for a few hours before the site goes down completely. I'm thinking  these errors have to do with certain threads having connectivity issues with the database. I don't see any error that seems to trigger the process, or a final error that causes the site to stop working completely.

Thanks!

I have checked the active processes in the database, and there aren't any for that database after the site goes down. That, along with the fact that the problem is fixed by a re-boot of the server that has IIS running, leads me to believe it is an issue with my IIS server losing connectivity to the db server, although as I mentioned, I can still ping the db server from the IIS server.