Distributed Consensus - Raft Leader Election | Systems Design Interview 0 to 1 with Ex-Google SWE

Would anyone like to propose themselves as candidate for epoch 2 of my girlfriend (please I'm begging)

[ololga]

In the past I didn't enjoy system design, but after trying it with Jordan my life changed and I started enjoying it.
Thanks, Jordan for making all these videos!

[jporritt]

I appreciate this length of video. Really convenient for getting complex topics.

[sahilkalamkar]

At 7:52, so essentially if there is a node which has more up to date logs then the leader being considered for election, those extra writes will be ignored if someone else is chosen as leader?

[msebrahim-]

1 - (4:05) In general, how can a follower be behind the current term number? Does this imply the follow node went down and came back up at a time when there was a new term?

2 - (4:35) How is it possible that a follower is in a term number that is greater than or equal to the term number that is being proposed? Once again i'm thinking that this follower perhaps went down and is massively behind when it comes back online?

As a follow up to this question, if this implies that there is already a leader for term 29, shouldn't the candidate stop its proposal altogether since there is already a leader for term 29?

[yrfvnihfcvhjikfjn]

This dude is casually bragging about leaving his house. Smh not even a real shut in

[reddy]

Suppose we have 5 nodes A B C D E, A is the current leader and it went down, B proposes and gets a yes from C and does not get a reply from other nodes and so B considers itself leader, At the same time D also proposes and gets a yes from E and does not get a reply from other nodes, Since both B and D got majority votes both will think they are the leader right?

[bokistotel]

@6:48 "If an older leader proposes a write with a lower epoch number than a current token we KNOW that it is an old leader". My question is why do we know for certain that is was an old Leader? Couldn't it be an old Follower that updated its epoch number? Or are we assuming that this is a single leader replication and the one who proposes a write by definition must be/was a leader ?

[dwivedys]

Pretty, pretty tough! Consensus is as tough in tech as it is in real life I guess….

[sebuszqo]

hi, so what in case when we have 3 nodes and leader goes down? then election is 50:50? One node will say I am a candidate and if second one say "yes you are" everything is fine but what if the second node will say "no"?

[PrabhuMarappan]

At 2:51, you say that each node complains after random unit of time. But is that because each node has a different time to wait till the next heartbeat or is there? Or both are different?

[rahullingala]

How do the nodes know how much of it's log it should communicate with the other nodes?
Won't the logs be too huge?