Thanks for the help, Michael.

I know that it did not exist in IIS 7.5 unless installed as an add on extension. My point was that it work fine before - without the extension - so it should work fine now as well, as the feature is not enabled in the new server.

The problem is not to keep the app alive - it's a high-traffic site. But when updating DLL's, changing the web.config etc. the app pool recycles. That should not be a problem, but only "pause the site" for 20-30 seconds. But now it causes hard 503-errors for several minutes before coming back online. Event log is flooded with SQL Server timeout errors. It doesn't make sense to me. But I'm investigating that right now.

However, I'm sure it's not related to the topic question of whether DNN can run on Windows Server 2019.

I have upgrade my site to DNN 9.6.1 and the next step is to migrate to a new VM with Windows Server 2019 + SQL 2019 on the same VM. There is really no reason to run the SQL on a separate VM

Posted By allane on 13 May 2020 02:37 PM

The problem is not to keep the app alive - it's a high-traffic site. But when updating DLL's, changing the web.config etc. the app pool recycles. That should not be a problem, but only "pause the site" for 20-30 seconds. But now it causes hard 503-errors for several minutes before coming back online. Event log is flooded with SQL Server timeout errors. It doesn't make sense to me. But I'm investigating that right now.

The reason for the issues you have are in the connection between your server that runs IIS and the server that runs SQL. How is that organized? What Hypervisor do you use?

I tend to agree (DB on the webserver). When implementing a brand new server, I followed "best practices" and split the web- and db-server. In theory it's a good idea, but in reality it introduces all sorts of new complexities, including security and authentication issues.

It sounds like you have an idea about my issue - I would really appreciate input on which direction to look. Sorry for "hijacking" you forum topic :)

My setup is organized like this:
- Windows Server 2019 with Hyper-V role (as host)
- Webserver and DB on two separate Hyper-V virtual machines
- No DHCP or domain server. Both VMs has hardcoded IP-addresses
- SQL Server is set to allow remote connections with IP-restrictions in Windows Firewall allowing only the webserver to connect
- SQL Server is configured to allow "unlimited concurrent connections".

The errors occuring in the DNN event log is:

System.InvalidOperationException: Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached

The error is at: System.Data.ProviderBase.DbConnectionFactory.TryGetConnection

Hi,

how did you implement the user that accesses SQL Server? Is it the App Pool, or are you using an SQL Login?

Are the two servers (SQL and Web) members of a (Windows) domain?

Happy DNNing!
Michael

 

When splitting the servers I switched to SQL Server connection mode with a SQL user and the username + password written in the connection string.

The Hyper-V host and virtual servers are not members of a domain. The physical server is located at a external server center and is only used for hosting websites.

OK, that should work... I have this configuration in a DMZ with three webservers (using different systems, one of them is hosting some DNN sites) and one SQL Server. No problem so far.

What I have done was not using the IP Address of the SQL Server, but the real name of the server. To resolve that I added an entry in the hosts file (Windows\System32\drivers\etc\hosts). I can't imagine that this solves the problem, but maybe it's worth a try.

Happy DNNing!
Michael