No, it's not complicated. But for the people who don't understand zk deeply, they would easily ignore the fact that they would miss events in some way. Moreover, I think providing persistent watch is good for developers to build the "state-machine" application. Actually, HBase suffer from missing the intermediate state when use zk to store the data.
If the feature is implemented, I would like to see the patch and consider if it can be used for us. ________________________________________ From: Flavio Junqueira [[email protected]] Sent: Friday, January 17, 2014 8:12 PM To: [email protected] Subject: RE: Where are we in ZOOKEEPER-1416 My take is that persistent subscriptions add complexity and are not strictly necessary. You can follow this pattern of setting a watch, reading the state upon a notification and setting a new watch. Why do you feel that's complicated? -Flavio -----Original Message----- From: 陈迪豪 [mailto:[email protected]] Sent: Friday, January 17, 2014 3:13 AM To: [email protected] Subject: Where are we in ZOOKEEPER-1416 Persistent watch and implementing the feature to act like "state machine" which is mentioned in ZOOKEEPER-153<https://issues.apache.org/jira/browse/ZOOKEEPER-153>, would be great for ZooKeeper user. I think HBase would like to know all the change in zk rather than missing kind of events. So, would we continue developing these features? It's also a little complicated to develop with zk and I think there're lots of things to improve.
