The NetKernel Deadlock Detector is a powerful tool to for production NetKernel deployments. It can be used to automatically detected and rectify common liveness problems which could effect stability of a system.
The Configure Deadlock Detector tool on the Control Panel can be used to configure the various aspects of detection.
A global inactivity period can be specified in the tool which is used in deciding whether a request is live. This can be overridden on a per request basis by specifying a "liveness" header with a millisecond period.