Module org.jgroups.raft

Package org.jgroups.protocols.raft

Class Follower

java.lang.Object

org.jgroups.protocols.raft.RaftImpl

org.jgroups.protocols.raft.Follower

Direct Known Subclasses:

Learner

public class Follower
extends RaftImpl

Implements the behavior of a RAFT follower

Since:

0.1

Author:

Bela Ban

Field Summary

Fields inherited from class org.jgroups.protocols.raft.RaftImpl

raft

Constructor Summary

Constructors

Constructor	Description
Follower(RAFT raft)

Method Summary

Modifier and Type	Method	Description
void	handleInstallSnapshotRequest(org.jgroups.Message msg, org.jgroups.Address leader, long last_included_index, long last_included_term)	Called when a snapshot sent by the leader is received by a follower.

Methods inherited from class org.jgroups.protocols.raft.RaftImpl

destroy, getFirstIndexOfConflictingTerm, handleAppendEntriesRequest, handleAppendEntriesResponse, init, raft, raft

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Follower

public Follower(RAFT raft)

Method Details

handleInstallSnapshotRequest

public void handleInstallSnapshotRequest(org.jgroups.Message msg,
 org.jgroups.Address leader,
 long last_included_index,
 long last_included_term)

Description copied from class: RaftImpl

Called when a snapshot sent by the leader is received by a follower. The follower needs to overwrite its snapshot file with the received bytes and reinitialize its log to last_inluded_index and create a dummy LogEntry with last_included_term at last_included_index. This is needed by the next RaftImpl.handleAppendEntriesRequest(LogEntries, Address, int, int, int, int) call to compare to the previous index and term.

Overrides:

handleInstallSnapshotRequest in class RaftImpl

Parameters:

msg - The snapshot message sent by the leader

leader - The leader (= sender of the message)

last_included_index - The last index that's reflected in the state (=snapshot) sent by the leader. Indices first_appended, commit_index and last_appended have to be set to last_included_index

last_included_term - The last included term. The dummy entry needs to have this term, for comparison in the next handleAppendRequest() call.