Please provide an implementation/fix and submit a pull request on Github. I also have a related question about not only re-use the znode, but imho, It would be great that LeaderLatch can survive from teomprary ConnectionLossException (i.e., due to transient network issue). Technically, this is already the case. When a RECONNECTED is received, LeaderLatch will attempt to regain leadership. The problem is that when there is a network partition there is no way to guarantee that you are still the leader. If there is Quorum in another segment of the cluster a new leader might be elected there.
-JZ From: chao chu [email protected] Reply: [email protected] [email protected] Date: March 10, 2014 at 9:39:50 AM To: [email protected] [email protected] Subject: Re: Leader Latch recovery after suspended state Hi, Just want to see if there is any progress on this? I also have a related question about not only re-use the znode, but imho, It would be great that LeaderLatch can survive from teomprary ConnectionLossException (i.e., due to transient network issue). I guess in most cases, the context switch due to leader re-election is quite expensive, we might not want to do that just because of some transient issue. if the current leader can re-connect within the session timeout, it should still hold the leadership and no leader change would happen during between. The similar rational like the differences between ConnestionLossException (which is recoverable) and SessionExipredException (which is not recoverable). what are your thoughts on this? Thanks a lot! Regards, On Wed, Aug 21, 2013 at 2:05 AM, Jordan Zimmerman <[email protected]> wrote: Yes, I was suggesting how to patch Curator. On Aug 20, 2013, at 10:59 AM, Calvin Jia <[email protected]> wrote: Currently this is not supported in the Curator library, but the Curator library (specifically leader latch's reset method) is the correct/logical place to add this feature if I want it? On Tue, Aug 20, 2013 at 10:34 AM, Jordan Zimmerman <[email protected]> wrote: On reset() it could check to see if its node still exists. It would make the code a lot more complicated though. -JZ On Aug 20, 2013, at 10:25 AM, Calvin Jia <[email protected]> wrote: A leader latch enters the suspended state after failing to receive a response from the first ZK machine it heartbeats to (takes 2 thirds of the timeout). For the last 1 third, it tries to contact another ZK machine. If it is successful, it will enter the state reconnected. However, on reconnect, despite the fact the original node it created in ZK is still there, it will create another ephemeral-sequential node (the reset method is called). This means it will relinquish leadership, if there is another machine with a latch in the same path. Is there any way to reconnect and reuse the original ZK node? Thanks! -- ChuChao
