Not sure if this helps but here is an example:
- Txn T is acknowledged by A and B (ensemble is {A, B, C})
- Ensemble changes to {B, C, D}
- C and D form a quorum and elect C because it has the highest zxid.
C won't have T, so the txn gets lost.
Does it make sense?
-Flavio
> -----Original Message-----
> From: Jordan Zimmerman [mailto:[email protected]]
> Sent: 14 June 2013 19:35
> To: [email protected]
> Subject: Rolling config change considered harmful?
>
> I'm trying to track a race issue in our ZK usage. In debugging, I've come
to
> wonder if the way we do rolling config ensemble changes is the culprit.
How
> does ZK internal leader election work if the list of servers is not
consistent on
> each instance. e.g. Given 3 instances A B C and new instance coming online
D.
> If A and B think the server list is (A, B, C) but C and D think the
server list is (B,
> C, D) how does ZooKeeper handle leader election?
>
> -Jordan
