Process Placement versus Process Migration

Process placement entails selecting a suitable node for a given process to execute. In other words it is simply a remote execution facility. Migration involves interrupting a running process and restoring it on a different computer. Migration is rather more costly than placement, since the amount of state and the complexity of obtaining it increases significantly once a process begins execution. In addition, the whole process of migration involves a significant amount of computational overhead, so determining whether there is likely to be a performance improvement is non-trivial. Krueger and Livny [#KruegerACOPA##1#] investigated whether the addition of a migration facility to a distributed scheduler already capable of process placement would significantly increase performance or not. They found that, whilst placement alone is capable of a large improvement in performance, the addition of migration achieves considerable additional improvement in many cases. The magnitude of the performance improvement is dependent on several conditions: This conclusion is, however, contentious. According to Eager <#2759#> et al.<#2759#> [#EagerTLPBO##1#]: