M. M. Theimer, K. A. Lantz, and D. R. Cheriton. Preemtable remote execution facilities for the V-system. Proceedings of the 10th ACM Symposium on Operating System Priniples, December 1985.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....for Storing State In moving from one host to the next, any agent whose future actions depend on its past execution must be accompanied by state. With strong mobility, state capture is automatic and complete not unlike what is done in operating systems that support process migration [Zay87, TLC85, PM83] where the system extracts the state of a process, moves it to another processor, and then starts the process running there. Determining which state components to extract for a given process has proved tricky and expensive for process migration in the presence of run time stacks, caches, ....

M. M. Theimer, K. A. Lantz, and D. R. Cheriton. Preemtable remote execution facilities for the V-system. Proceedings of the 10th ACM Symposium on Operating System Priniples, December 1985.

....another if the latter site wants to modify the object. This model is neither a client server model nor is it possible to move a set of objects to a specific site. Research has been conducted in the area of process migration for various operating environments. Systems such as Sprite [Douglis91] V [Theimer85], DEMOS MP [Powell83] and Accent [Zayas87] support this facility. Some of the problems faced in process migration schemes are similar to the ones faced in Thor, e.g. forwarding pointers have to be left at the old site and all relevant operations have to routed to the new site. But there are other ....

Theimer M. M., Lantz K. A., Cheriton D. R. Preemtable Remote Execution Facilities in for the V-system. Proceedings of the Tenth ACM Symposium on Operating Systems Principles, pages 2-12, December 1985.

....With respect to the checkpoint migration facility, two operation levels are distinguished: operating system level and user level. In operating system level implementations the resource management facilities are supported by the OS kernel. Examples of such systems are Mach [9] V Kernel [14], Sprite [5] and Charlotte [2] User level designs and implementations of adaptive systems include dynamic resource management facilities by providing their own dynamic load balancing run time support. Examples of user level designs are Condor [8] for sequential, and MPVM [3] for parallel ....

....link, without interference of the PVM daemons and thereby enhancing communication performance (see for example TCP connection between tasks a1 and c1 in Fig. 1) 2. 2 Aspects of Checkpoint and Migration Systems supporting dynamic load balancing, such as Charlotte [2] Condor [8] or V System [14], stem from the observation that many of the constantly increasing number of workstations in academic and industrial institutions are lightly loaded on the average. In general, workstations are intended for personal usage, which has a typical activity pattern that machines are only 5 pvmd A ....

M. M. Theimer, K. A. Lantz, and D. R. Cheriton. Preemtable remote execution facilities for the V-System. In Proceedings of the 10th ACM Symposium on Operating System Principles, pages 2--12, Orcas Islands, Washington, Dec. 1985.

....time. Pages which are needed later were transmitted on demand. This method leaves the data of one process distributed over different sites and is therefore sensitive to processor crashes. The advantage is that only the pages which are needed have to be transmitted. ffl Researchers at Stanford [TLC85] did the same from the opposite direction. The process continues to run on the old host and pages are copied to the new one. When a page is copied it is marked as clean; when the running process modifies this page then it is marked as dirty. When the first round of copying is completed the dirty ....

M.M. Theimer, K.A. Lantz, and D.R. Cheriton. Preemtable remote execution facilities for the v-system. In Proceedings of the Tenth Symposium on Operating System Principles, pages 2--12, Orcas Island, WA, 1985.

....created from scratch on the target processor. Program text may be located and loaded from a local or a distributed file system on the target processor. The problem is then a matter of achieving the illusion for the user that the process is running locally. 2.2.2 Non preemptive vs. Preemptive In [TLC85, Gos91, DO87] there is a notion of private processors. A workstation belongs to whatever person is sitting in front of it at the moment, and that person should have all resources available to him. If the workstation is idle, its computing resources could be made available for other users 3 . In ....

....of this method is that the migrating process may be suspended unnecessary long. However, it is simple and straightforward to implement. It may be better to let a process continue executing while pages are copied to the target processor. This is called pre copying and is used in the V system [TLC85] Every page copied, is marked clean. If the process modifies a clean memory page after it has been copied, it is marked dirty. When all pages are copied across, the process is suspended. The problem is that memory pages at the source processor may have been modified after they were copied ....

M. M. Theimer, K. A. Lantz, and D. R. Cheriton. Preemtable remote execution facilities for the V-system. Proceedings of the 10th ACM Symposium on Operating System Priniples, December 1985.

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