Chandy–Lamport algorithm: Difference between revisions

Revision as of 17:30, 30 June 2007

Revision as of 03:47, 31 January 2008

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* Each process in the system records its local state and the state of its incoming channels

The algorithm works using marker messages. Each process that wants to initiate a snapshot records its local state and sends a marker on each of its outgoing channels. All the other processes, upon receiving a marker, record their local state, the state of the channel from which the marker just came as empty, and send marker messages on all of their outgoing channels. If a process receives a messagemarker after having recorded its local state, it records the state of the incoming channel from which the marker came as carrying all the messages received since it first recorded its local state.

Some of the assumptions of the algorithm can be facilitated using a more reliable communication protocol such as [[Internet protocol suite|TCP/IP]]. The algorithm can be adapted so that there could be multiple snapshots occurring simultaneously.