Load Balancing with Migration Based on Synchronizers in PS-GRADE Graphical Tool

Parallel application control based on application global states is a new concept realized in PS-GRADE. PS-GRADE is a graphical environment for parallel programming, which unifies message passing programming style with control based on global application states. Special processes called synchronizers are responsible for gathering process states, constructing application global states and issuing control signals when necessary to application processes. In this paper, we show how this mechanism can be used as a framework for implementing load balancing with process migration using several methods. With some of these methods, synchronizers collect strongly consistent states of processor loads in the system and workout load balancing decisions including process migration. Asynchronous control signals from synchronizers break current computations and cause a process to migrate onto a less loaded host. Another signal activates a target process and activates restoring of the captured state in it. With other methods we use a special PVM library _ynamite PVM instead of a standard version. It extends PVM by checkpointing and process migration with full restoration of the process state