Survey of Systems Providing Process or Object Migration Imperial College Research Report Doc 94/10

This report details a survey of systems providing process or object migration. After an introduction to the topic a number of systems are covered in detail. Four chapters deal with systems providing migration over unmodi ed UNIX, those providing \classical" process migration and containing modi ed or new kernels, migration over modern microkernel based operating systems and nally those providing more general \object" migration. The coverage of each system contains a general overview, a detailed examination of the migration subsystem and load balancing support, if any. Migration support is sectioned into an overview, an examination of the migration mechanisms, the e ects of migration on inter (task) communication, and details of any environment and associated resource transfer. The summary provides comments on the major design issues identi ed within the report. It notes that solutions running over raw UNIX are the least complete, and that some level of kernel modi cation is generally necessary in order to provide good migration support. Microkernel architectures are shown be useful to the developers of a migration subsystem due to their modularity, which tends to ease the encapsulation of process state. The \object" paradigm is similarly shown to aid both encapsulation and post migration communication. Finally, a note is made that very few research topics seem to remain in the construction of a process migration system since the majority of design issues have now been addressed. No one system is found to provide a complete range of features, however.