Correct. And even simple connection losses can cause watches to become unreliable as well:
http://zookeeper.apache.org/doc/trunk/releasenotes.html#Watch+Management "One caveat to the watch management: it is possible to miss an event for the creation and deletion of a znode if watching for creation and both the create and delete happens while the client is disconnected from ZooKeeper." Best Regards, Martin Kou On Fri, May 18, 2012 at 8:33 PM, 李赫元 <[email protected]> wrote: > Thanks for your help. > That means we can't totally rely on watchs because it may loss event if > session expired, right? > > 在 2012年5月19日星期六，Camille Fournier <[email protected]> 写道： > > I'm not sure what you mean in question #1. A session expired event > > generally causes the client to become completely invalid, you could > > wrap the client in your own logic to record what you were watching, > > but I don't think you can get that out of the client after it's > > expired. > > > > 2. You won't be able to see events that happened when the session was > > expired. The server has closed your connection and won't know to send > > you events unless you have a valid session with a valid watch. > > > > 3. Reconnect won't work on expired sessions, you need to create an > > entirely new session. Reconnect works when you get disconnected but > > not expired. > > > > Hope that helps > > On Fri, May 18, 2012 at 12:18 PM, 李赫元 <[email protected]> wrote: > >> Hi, All > >> > >> I'm dealing with the case of "session expired" event. Please help me > >> with the following question. > >> > >> 1. After receive "session expired" event, how to recover the watch > >> that are setting before expired gracefully? > >> > >> > >> 2.Currently, I record the watch setting and call the api to set it > >> again after I got "expired event". It will callback for event after > >> connection was success again. But what about the event happend between > >> I success reinit the session to zk server. Currently, it got lost. Is > >> there any way that I can got these events ? > >> > >> > >> 3.I try to use reconnect, in zookeeper_init, but does't work. My guess > >> is reconnect is only work for connection that are in state connect > >> (Not valid after session timeout), is it right? > >> > >> > >> Thanks for your help ! > > >
