But you don't really miss events, you'll see them when you read the ZK state. If you follow the pattern I described, you're supposed to observe all changes. Perhaps I'm missing some concrete use case you have mind.
-Flavio > -----Original Message----- > From: 陈迪豪 [mailto:[email protected]] > Sent: 17 January 2014 13:03 > To: [email protected] > Subject: RE: Where are we in ZOOKEEPER-1416 > > 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.
