zookeeper-user mailing list archives

Tom White wrote:
> If client sets a watcher on a znode by doing a getData operation is it
> guaranteed to get the next change after the value it read, or can a
> change be missed?

> In other words if the value it read had zxid z1 and the next update of
> the znode has zxid z2, will the watcher always get the event for the
> change z2?

Yes, that is a strong guarantee. See the following:
http://hadoop.apache.org/zookeeper/docs/r3.0.1/zookeeperProgrammers.html#sc_WatchGuarantees

Patrick