Automatic software upgrade for distributed systems. PHD THESIS MIT by Sameer Ajmani ( 2004 )
Problem thesis address:
All nodes cannot be upgraded simultaneously . This will halt the system.
Incompatible protocols if non simultaneous upgrade. The solution by Ajmani and Oxygen group, UpSTART.
Scheduling function that schedule the task, transform function that control persistent state, simulation object that enable the system
to run in mixed mode