This election algorithm is based on the use of a ring. We assume that the processes are physically or logically ordered, so that each process knows who its successor is. When any process notices that the coordinator is not functioning, it builds an ELECTION message containing its own process number and sends the message to its succesor. If the succesor is down, the sender skips over the successor and goes to the next number along the ring, or the one after that, until a running process is located. At each step, the sender adds its own process number to the list in the message.
Eventually, the message gets back to the process that started it all. That process recognizes this event when it receives an incoming message containing its own process number. At that point, the message type is changed to COORDINATOR and circulated once again, this time to inform everyone else who the coordinator is (designated by the list member with the highest number) and who the members of the new ring are. When this message has circulated once, it is removed and everyone goes back to work.
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