I have opened ZOOKEEPER-261 for this issue. it shouldn't be too hard to fix and
it would be nice to target for 3.1.
From: thomas.john...@sun.com [mailto:thomas.john...@sun.com]
Sent: Wednesday, December 17, 2008 2:52 PM
Subject: Re: What happens when a server loses all its state?
Thanks for all the responses.
Benjamin Reed wrote:
> in the scenario you give you have two simultaneous failures with 3 nodes, so
> it will not recover correctly. A is failed because it is not up. B has failed
> because it lost all its data.
> it would be good for ZooKeeper to not come up in that scenario. perhaps what
> we need is something similar to your safe state proposal. basically a server
> that has forgotten everything should not be allowed to vote in the leader
> election. that would avoid your scenario. we just need to put a flag file in
> the data directory to say that the data is valid and thus can vote.
Would this feature be something you'd consider implementing in the short
to medium term?