ASP.NET 4.5.1 App Suspend is the managed implementation of this new functionality and will improve the startup time of your .NET web applications running in IIS. The .NET Framework Blog explains that this is perfect for hosting companies but even if you’re only running a single site you’ll feel the difference.
The IIS Idle Worker Process Page-Out option was introduced in IIS 8.5 and it allows IIS to “suspend” applications that may become idle rather than terminating them. This suspension will enable these applications to be very quickly restarted when requested as opposed to if they were terminated, which would require the server to spin up and essentially experience a “cold start”.
Suspended Sites , it is mean the sites that may have been previously running and have been “paged-out” into memory and suspended through App Suspend and are awaiting to be “re-animated”. Suspended sites receive far less CPU cycles and system memory, which can be allocated to other active sites that need it.
Now let’s see how we can enable App Suspend for web applications running in a Web Role.
1. Open the IIS Manager (available through the Control Panel > Administrative Tools > Internet Information Services (IIS) Manager)
2. Click on the Application Pools that you want to target on the left.
3. Right-click on the Application Pool that you want to enable App Suspend for on the right; Select the Advanced Settings option from the context menu.
4. Find the Idle Time-Out Action property and set it to Suspend.
What to Expect?
An analysis from the .NET team saw outstanding results through this simple change within their hosting environments, but the two major benefits boil down to the points below:
Dramatically Increased Start-up Times – You can reasonably expect up to a 90% drop in start-up times for your applications that are running with App Suspend.
Improved Hosting Density – Due to the way that suspended applications are stored, they use a fraction of the resources they normally would. This can allow you to increase the number of sites by up to 7 times that you could previously host without App Suspend.
You might not experience exactly the same benefits (obviously if your hardware can’t support it, don’t risk trying to add 10x the number of sites you normally host), but you should certainly see faster start-up times across all of the sites that you are running within the targeted Application Pools.
That’s all about How to Enable App Suspend in ASP.NET 4.5.1 , for more information about ASP.NET 4.5.1 Hosting please visit ASPHostPortal.com.