I also opened an jira CURATOR-330 on this. From: Wang, Simon Sent: Monday, May 23, 2016 5:14 PM To: [email protected] Subject: Connection lost handling when entering double barrier
Here is the problem I'm meeting: Assuming 3 node ensemble, my application has 3 clients and each one runs on same zk node (Client 1, 2 and 3). They use double barrier for coordination. Client 1 is entering the barrier and waiting for the other 2. Now the other 2 nodes are down and then the ensemble gets crashed and the client 1 gets LostConnectionException from enter(). That's expected. After while the other 2 nodes come back, all clients need to retry operation and reenter the same barrier (It might become more complex if creating a new barrier). Here is the problem: If the session for client 1 is still alive, Client 1 calling enter method will get NodeExistException as the ephemeral node corresponding to that session is not deleted yet. I wonder in this case what should I do from application side? Or I'm thinking can we add a mechanism to reenter the barrier but skip creating child node for this client if that exists? I would like to open a Jira for this if required. Thanks, Simon
