Hi,
On 12 June 2014 08:40, Mudit Verma <[email protected]> wrote: > Hi All, > > In my last couple of projects, I have heavily used zookeeper watches. > However, ZK watch is a one time event. > > I strongly feel that zookeeper should have a way to set a watch > permanently (unless removed by the user through an API or the znode is > deleted). This would guarantee that no data change event is missed by the > client. Otherwise, we can miss data change event that occurs between > receiving the call back from previous watch and resetting the new watch > again. This problem is also stated in documentation. > > I am sure even others might have felt this need sometime or the other. > This missing capability makes ZK watcher functionality best effort and not > full proof. Consequently, clients who can not afford to miss any event, > can not use ZooKeeper reliably. > > I think we should have these APIs unless there is some theoretical or > practical problem with these. > > 1. API to set a watch permanently. > 2. Removing a watch when not needed. > > > Looking forward for a discussion. > Perhaps: https://issues.apache.org/jira/browse/ZOOKEEPER-1416? -rgs
