Background

When SharePoint 2013 installs IIS application pools are created for content, service applications, central admin, and workflow.    Only the content pools appear to be given a daily recycle time.    However, I have noticed errors with Service Applications which can be fixed after recycling the pool.    Personally I prefer to recycle pools daily and ensure maximum stability.   Below is PowerShell code to accomplish that.  

Symptoms

• Excel Services Web Part error visible to end users –  “We don’t know what happened, but something went wrong.  Could you please try that again?”
• WCF errors on eventlog
• Slow or unresponsive HTTP endpoints with “.svc”

Resolution

Apply 1AM IIS daily recycle time to any SharePoint pools without a schedule.

PowerShell Code

# Bypass IIS Defaults
$exclude=@(".NET v2.0",".NET v2.0 Classic",".NET v4.5",".NET v4.5 Classic","Classic .NET AppPool","DefaultAppPool");
# Loop SharePoint pools
$pools = Get-ChildItem IIS:\AppPools;
foreach ($p in $pools) {
	if (!$exclude.contains($p.name)) {
		$pn = $p.Name;
		$s = $p.recycling.periodicRestart.schedule.collection.value;
		if (!$s) {
			# Missing recycle schedule.  Set 1AM daily
			Set-ItemProperty -Path "IIS:\AppPools\$pn" -Name Recycling.periodicRestart.schedule -Value @{value="01:00"}}
		}
	}
}