Bryce, I'm not sure about ZooKeeper, but I know if you have a partition between HazelCast nodes, than the nodes can acquire the same lock independently in each divided partition. How does ZooKeeper handle this situation?
-- Drew On Jan 6, 2012, at 12:48 PM, Bryce Allen wrote: > On Fri, 6 Jan 2012 10:03:38 -0800 > Drew Kutcharian <d...@venarc.com> wrote: >> I know that this can be done using a lock manager such as ZooKeeper >> or HazelCast, but the issue with using either of them is that if >> ZooKeeper or HazelCast is down, then you can't be sure about the >> reliability of the lock. So this potentially, in the very rare >> instance where the lock manager is down and two users are registering >> with the same email, can cause major issues. > > For most applications, if the lock managers is down, you don't acquire > the lock, so you don't enter the critical section. Rather than allowing > inconsistency, you become unavailable (at least to writes that require > a lock). > > -Bryce
