I have also experienced 3 delete events in the last year when there were no actual deletes in ZK. I was using the delete events as a trigger to do an actual deletion in the system. Since we experienced false deletes, I had to rethink the way I was using the PathChildrenCache.
Thank you, Curtis Cantrell From: Benjamin Jaton [mailto:[email protected]] Sent: Monday, October 24, 2016 7:34 PM To: [email protected] Subject: Re: Curator PathChildrenCache sends delete events but no delete happened Hi Cameron, thanks for your answer. Yes I noticed that too, it seems to be coming from the ZK client layer. I have tried to use the ZK Watcher API but I couldn't reproduce the issue when I was using them. I will have a look at how PathChildrenCache does it and keep you posted. Thanks Benjamin On Mon, Oct 24, 2016 at 4:08 PM, Cameron McKenzie <[email protected]<mailto:[email protected]>> wrote: hey Benjamin, I'm not aware of any such edge cases, but that does not mean that they don't exist. From the log: 2016-10-24 15:52:43 DEBUG o.a.z.ClientCnxn:889 - Got WatchedEvent state:SyncConnected type:NodeDeleted path:/benji2/123 for sessionid 0x20014cf3d480003 This is being logged by the Zookeeper client itself that Curator is using. So it doesn't appear to be Curator inferring some sort of delete event. It looks like an explicit watched event coming from Zookeeper. cheers On Tue, Oct 25, 2016 at 10:04 AM, Benjamin Jaton <[email protected]<mailto:[email protected]>> wrote: Hello, I am using PathChildrenCache and I am receiving delete events even if there is no actual delete in ZK. I printed the WatchedEvent details for 2 of those delete events (of the same node /benji2/123) I received in the same JVM run: 2016-10-24 15:52:43 DEBUG o.a.z.ClientCnxn:889 - Got WatchedEvent state:SyncConnected type:NodeDeleted path:/benji2/123 for sessionid 0x20014cf3d480003 [PathChildrenCacheListener] delete event for /benji2/123 PathChildrenCacheEvent{type=CHILD_REMOVED, data=ChildData{path='/benji2/123', stat=19808389169191,19808389169191,1477335789916,1477335789916,0,0,0,0,0,0,19808389169191 , data=[]}} null ChildData{path='/benji2/123', stat=19808389169191,19808389169191,1477335789916,1477335789916,0,0,0,0,0,0,19808389169191 , data=[]} getAversion=0 2016-10-24 15:52:43 DEBUG o.a.z.ClientCnxn:867 - Got notification sessionid:0x20014cf3d480003 getCtime=1477335789916 getCversion=0 getCzxid=19808389169191 getMtime=1477335789916 2016-10-24 15:52:43 DEBUG o.a.z.ClientCnxn:889 - Got WatchedEvent state:SyncConnected type:NodeDeleted path:/benji2 for sessionid 0x20014cf3d480003 getMzxid=19808389169191 getPzxid=19808389169191 getVersion=0 (...) 2016-10-24 15:58:06 DEBUG o.a.z.ClientCnxn:889 - Got WatchedEvent state:SyncConnected type:NodeDeleted path:/benji2/123 for sessionid 0x20014cf3d480003 [PathChildrenCacheListener] delete event for /benji2/123 PathChildrenCacheEvent{type=CHILD_REMOVED, data=ChildData{path='/benji2/123', stat=19808389169191,19808389169191,1477335789916,1477335789916,0,0,0,0,0,0,19808389169191 , data=[]}} null 2016-10-24 15:58:06 DEBUG o.a.z.ClientCnxn:867 - Got notification sessionid:0x20014cf3d480003 ChildData{path='/benji2/123', stat=19808389169191,19808389169191,1477335789916,1477335789916,0,0,0,0,0,0,19808389169191 , data=[]} getAversion=0 getCtime=1477335789916 getCversion=0 getCzxid=19808389169191 getMtime=1477335789916 getMzxid=19808389169191 getPzxid=19808389169191 getVersion=0 Are there known edge cases where this can happen? Again there is no delete at all in ZK, I verified the transaction log of ZooKeeper, no delete is present). Thanks, Benjamin The information contained in this message is proprietary and/or confidential. If you are not the intended recipient, please: (i) delete the message and all copies; (ii) do not disclose, distribute or use the message in any manner; and (iii) notify the sender immediately. In addition, please be aware that any message addressed to our domain is subject to archiving and review by persons other than the intended recipient. Thank you.
