Server 2012 r2 IIS stops responding

2 things are possibly contributing to this situation:

1. IIS Application Pool time

What is happening is that the AppPool that supports the website, is using the default settings which allow the AppPool to be shutdown after a defined period of time, when no activity is hitting the sites.

You can turn this off by doing the following:

1. Open IIS Manager
2. Locate the Application Pool for the website in question
3. Right-click on the AppPool and select "Advanced Settings"
4. Under the Process Model section, the third setting is labeled "Idle Time-Out (minutes), the default setting is 20 minutes.  Set this to 0.  This will tell IIS to never allow the AppPool to be shut down due to being idle for too long.

The second possibility, though less likely an issue, VMWare may be suspending the Virtual Machine after being idle for too long, to conserve power and resources for other VM guest OSes.

But I would first try reconfiguring the IIS AppPool to prevent Idle Time-Outs.

Dan

Does your system maintain logs, do you analyze those logs? Do you have application monitoring. Does the stopage always occur within a specific pattern, same time of the day, same time of xth day, etc.

once a pattern is determined, checking what else might be going with the back end i.e. if a database is used, what happens there during the same time frame.