research:dgc
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research:dgc [2006/07/01 12:59] – elisag | research:dgc [2006/07/01 13:37] – elisag | ||
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==== Motivation ==== | ==== Motivation ==== | ||
+ | CURRENTLY UNDER CONSTRUCTION! | ||
Mobile ad hoc networks represent a new kind of distributed system with distinguishing characteristics that pose new challenges in the field of distributed garbage collection (DGC). In particular, DGC must deal with a highly partial disconnected network topology where remote references may be inaccessible for unpredicted amount of time. DGC mechanisms typically determine the reachability of the remote objects by means of communication between the nodes involved. However, in a mobile setting where disconnections are the rule rather the exception, the system cannot determine how long it should wait for a connection to be restored. At best, the failure will be transitory and the created inaccessible reference will become accessible again by a repaired connection, but at worst the devices may never encounter again - e.g. when a user never comes back to a certain place - and an unbounded amount of inaccessible reference will be accumulated as they move about. | Mobile ad hoc networks represent a new kind of distributed system with distinguishing characteristics that pose new challenges in the field of distributed garbage collection (DGC). In particular, DGC must deal with a highly partial disconnected network topology where remote references may be inaccessible for unpredicted amount of time. DGC mechanisms typically determine the reachability of the remote objects by means of communication between the nodes involved. However, in a mobile setting where disconnections are the rule rather the exception, the system cannot determine how long it should wait for a connection to be restored. At best, the failure will be transitory and the created inaccessible reference will become accessible again by a repaired connection, but at worst the devices may never encounter again - e.g. when a user never comes back to a certain place - and an unbounded amount of inaccessible reference will be accumulated as they move about. | ||
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Semi-automatic garbage collection is a hybrid approach which relies on an underlying local GC and proposes a non-transparent DGC. The approach can be seen as an extension to the indirect reference counting (Piquer, | Semi-automatic garbage collection is a hybrid approach which relies on an underlying local GC and proposes a non-transparent DGC. The approach can be seen as an extension to the indirect reference counting (Piquer, | ||
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+ | {{ remoterefint.jpg? | ||
Since devices may not be able to communicate at some point in time, when a remote reference is first allocated both parties in the interaction will establish a contract with the condition under which the reference is useful to the application. Therefore, if one devices becomes inaccessible because of a broken connection, the other one is aware of the conditions in which the inaccessible reference is still valuable. We propose // | Since devices may not be able to communicate at some point in time, when a remote reference is first allocated both parties in the interaction will establish a contract with the condition under which the reference is useful to the application. Therefore, if one devices becomes inaccessible because of a broken connection, the other one is aware of the conditions in which the inaccessible reference is still valuable. We propose // |
research/dgc.txt · Last modified: 2015/02/04 19:10 by elisag