FreeBSD Developer: University of Melbourne
The FreeBSD Foundation is pleased to announce that Julien Ridoux and Darryl Veitch at the University of Melbourne have been awarded a grant to implement support of feed-forward clock synchronization algorithms.
The Network Time Protocol (NTP) is widely used for synchronization over the network and the ntpd daemon is the current reference synchronization algorithm. The system clock in FreeBSD is currently designed with ntpd in mind, leading to strong feedback coupling between the kernel and the synchronization daemon.
The RADclock is an example of an alternative class of synchronization algorithms based on feed-forward principles. This project will provide the core support for feed-forward algorithms, so that alternatives to ntpd can be developed and tested. The central motivation for this is the strong potential of such approaches for highly robust and accurate synchronization.
Beyond this, virtualization is one of the next major challenges faced by time keeping systems. The current feedback synchronization model is complex and introduces its own dynamics, an approach that is not suited to the requirements of virtualization. Feed-forward based synchronization offers a cleaner and simpler approach, which is capable of providing accurate time keeping over live migration of virtual machines.
This project completed in September 2011.