Prepare is only sent to either establish a leader else to probe for the uncommitted values of a previous leader during the leader take-over phase. Followers must:
1. Check the BallotNumber of the Identifier against the highest value previously acknowledged; if the request is lower acknowledged negatively acknowledge (“nack") it.
1. Check the logIndex of the Identifier against the highest committed logIndex; if the request is lower nack it.
1. If the BallotNumber of the Identifier is higher the then previously acknowledged the node must make the new number durable and promise to nack any messages with a lower BallotNumber The positive acknowledgement ("ack") must return the highest uncommitted Accept message with the same log index or None if there is no uncommitted value at that slot.
Linear Supertypes
Serializable, Serializable, Product, Equals, PaxosMessage, AnyRef, Any
Prepare is only sent to either establish a leader else to probe for the uncommitted values of a previous leader during the leader take-over phase. Followers must:
1. Check the BallotNumber of the Identifier against the highest value previously acknowledged; if the request is lower acknowledged negatively acknowledge (“nack") it. 1. Check the logIndex of the Identifier against the highest committed logIndex; if the request is lower nack it. 1. If the BallotNumber of the Identifier is higher the then previously acknowledged the node must make the new number durable and promise to nack any messages with a lower BallotNumber The positive acknowledgement ("ack") must return the highest uncommitted Accept message with the same log index or None if there is no uncommitted value at that slot.