Would my watcher get invoked on this ConnectionLoss event? If so I am thinking I will check for KeeperState.Disconnected and reset my state. Is my understanding correct? Please advice.
Thanks Avinash On Tue, Oct 12, 2010 at 10:45 AM, Benjamin Reed <br...@yahoo-inc.com> wrote: > ZooKeeper considers a client dead when it hasn't heard from that client > during the timeout period. clients make sure to communicate with ZooKeeper > at least once in 1/3 the timeout period. if the client doesn't hear from > ZooKeeper in 2/3 the timeout period, the client will issue a ConnectionLoss > event and cause outstanding requests to fail with a ConnectionLoss. > > So, if ZooKeeper decides a process is dead, the process will get a > ConnectionLoss event. Once ZooKeeper decides that a client is dead, if the > client reconnects, the client will get a SessionExpired. Once a session is > expired, the expired handle will become useless, so no new requests, no > watches, etc. > > The bottom line is if your process gets a process expired, you need to > treat that process as expired and recover by creating a new zookeeper handle > (possibly by restarting the process) and resetup your state. > > ben > > > On 10/12/2010 09:54 AM, Avinash Lakshman wrote: > >> This is what I have going: >> >> I have a bunch of 200 nodes come up and create an ephemeral entry under a >> znode names /Membership. When nodes are detected dead the node associated >> with the dead node under /Membership is deleted and watch delivered to the >> rest of the members. Now there are circumstances a node A is deemed dead >> while the process is still up and running on A. It is a false detection >> which I need to probably deal with. How do I deal with this situation? >> Over >> time false detections delete all the entries underneath the /Membership >> znode even though all processes are up and running. >> >> So my questions are: >> Would the watches be pushed out to the node that is falsely deemed dead? >> If >> so I can have that process recreate the ephemeral znode underneath >> /Membership. >> If a node leaves a watch and then truly crashes. When it comes back up >> would >> it get watches it missed during the interim period? In any case how do >> watches behave in the event of false/true failure detection? >> >> Thanks >> A >> > >
