NRG: Campaign early unless already candidate #6511
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Signed-off-by: Maurice van Veen <[email protected]>
MauriceVanVeen
commented
Feb 14, 2025
| @@ -4138,11 +4138,10 @@ func (n *raft) processVoteRequest(vr *voteRequest) error { | |||
| n.vote = vr.candidate | |||
| n.writeTermVote() | |||
| n.resetElectionTimeout() | |||
| } else { | |||
| if vr.term >= n.term && n.vote == noVote { | |||
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Have removed the vr.term >= n.term part of the condition as well as the n.term = vr.term as they don't do anything at the moment.
If vr.term < n.term we already deny requests, and if vr.term > n.term we update above. So when we come here vr.term == n.term already.
neilalexander
approved these changes
Feb 14, 2025
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If an outdated server wants to become leader, other servers can recognize they have a more up-to-date and start campaigning early to speed up the leader election process.
However, if two servers would both become candidate at the same time due to this, and one of the candidate's log is slightly more ahead it would again start campaigning early. This can essentially short-circuit the voting process, starting a new leader election/term while that wouldn't be necessary to do. That ahead candidate could just reject the vote for the other candidate, and wait for successful votes for itself to come in.
Signed-off-by: Maurice van Veen [email protected]