A machine snapshot is associated with a .NET agent. The .NET agent will monitor machine metrics like CPU, Memory, and IIS queue items. It takes a snapshot periodically once every 10 minutes. It will also take what is called ''Breached Snapshots''. This is where the CPU, Memory, or IIS queue has crossed a certain threshold. Once this happens it takes a snapshot of the machine once every 10 seconds for 10 minutes.

- The CPU must be 80% or higher
- The memory must be at 80% or higher
- The IIS queue items must be older than 100 ms

The Breached Snapshots begin once AppDynamics identifies 6 or more of the above violations within the 10 minute window. You can change these defaults in the config.xml file. You get the following information from a Machine Snapshot

- Processes, App Pools, and Transaction Snapshot
- Machine Name, Time Stamp, CPU, and Memory at the point of the Snapshot
- As well as all transaction snapshots involving the current machine five minutes before and after the machine snapshot.

You need IIS 7 or later and you must enable the Request Monitor for the IIS Monitoring feature in the IIS Web Server Manager, in order to get IIS App Pool information.