"If the group has 3 nodes, then the log entries in the leader A are not yet committed since the entries 7-10 have not replicated to a majority"
Entries 7-10 are committed because the group started with just 1 node which had majority of 1 Aftet that 2 blank nodes were added On Mon., Aug. 22, 2022, 10:27 p.m. Tsz Wo Sze, <[email protected]> wrote: > Hi Asad, > > If the group has 3 nodes, then the log entries in the leader A are not > yet committed since the entries 7-10 have not replicated to a majority > of nodes. The entries 7-10 can be either committed later or safely > thrown away: > > - If A becomes the leader again, it will resend the entries 7-10 to > the followers. > > - Suppose 2 nodes B and C have voted a new leader among themselves. > The new leader, say B, will first record a new log entry 7' for > starting a new term and send it to C. Once C has received 7', the > entry becomes committed. When A rejoins the group, A must truncate > its log and throw away entries 7-10. > > Hope it helps. > Tsz-Wo > > On Mon, Aug 22, 2022 at 2:04 PM Asad Awadia <[email protected]> wrote: > > > > Hello, > > > > What happens if the leader goes down while the follower nodes are still > catching up (like after just starting up) > > > > Eg > > 1 node is the leader and has logs from 0-10 > > 2 nodes join and start replicating the log > > After the 2 follower nodes get to log index 6 > > The leader goes down > > What happens to the log entries from 7-10? > > Are they thrown away? Now the new leader will overwrite? >
