Using DotNetNuke (DNN) on a Load Balanced Web Farm

DNN has been known to have cache issues, especially when used on a load balancer. Since the DNN community edition suffers from a lack of web farm support, caching always behaves unusual whenever a deployment is made. To avoid having to pay royalties and support fees to DotNetNuke for the enterprise edition, some companies opt for a work around the common cache problem. A quick and dirty way to solve this problem is to clear the cache and recycle the app pool.

To clear the DNN cache, one can go to Host > Schedule. For “Purge Cache” and “Purge Module Cache”, click the edit icon, then enable the schedule and run it. A hard refresh on the browser (usually CTRL F5) is also recommended.

When making changes to DNN on a web farm, it’s best to recycle the app pool. The command below will recycle the app pool

%systemroot%\system32\inetsrv\AppCmd.exe recycle APPPOOL MyAppPoolId

Using AppCmd, you can get a list of app pools by executing

%systemroot%\system32\inetsrv\AppCmd.exe LIST APPPOOL

Furthermore, this command can be wrapped in a powershell command and executed remotely

function RecycleAppPool($serverName, $appPoolId){
    Invoke-Command $serverName { param($appPoolId) %systemroot%\system32\inetsrv\AppCmd.exe recycle APPPOOL $appPoolId } -Args $appPoolId
}
$WEBPROD1 = "x.x.x.x";
$WEBPROD2 = "x.x.x.x";
RecycleAppPool $WEBPROD1 "SiteAppPoolId"
RecycleAppPool $WEBPROD2 "SiteAppPoolId"

To enable Powershell, you may need to run this command in CMD as an admin:

Set-ExecutionPolicy unrestricted

To enable powershell remoting, run the following command on the remote server you wish to control

Enable-PSRemoting -force
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