Using programmable NICs for time-warp optimization

This paper explores optimization of parallel discrete event simulators (PDES) on a cluster of workstations with programmable network interface cards (NICs). We explore reprogramming the firmware on the NIC to optimize the performance of distributed simulation. This is a new implementation model for distributed applications where: (i) application specific communication optimizations can be implemented on the NIC; (ii) portions of the application that are most heavily communicating can be migrated to the NIC; (iii) some messages can be filtered out at the NIC without burdening the primary processor resources; and (iv) critical events are detected and handled early. The combined effect is to optimize the application communication behavior as well as reduce the load on the host processor resources. We explore this new model by implementing two optimizations to a time-warp simulator on the NIC: (1) the migration of the global virtual time estimation algorithm to the NIC; and (2) early cancellation of messages in place upon early detection of rollbacks. We believe that the model generalizes to other distributed applications.