Hi Chris, *"The whole tree disappears when the last ephemeral leaf node is removed."*
I think parent node has to be container node for it it work, but container node <https://issues.apache.org/jira/browse/ZOOKEEPER-2163> was added post ZK 3.5. I am trying to get lock-recipe for ZK 3.4. Did you try to implement with just ephemeral nodes in version <= 3.4? Thanks, Rajat On Wed, Feb 5, 2020 at 11:32 AM Chris T. <c.turks...@gmail.com> wrote: > I have a type of locking mechanism using ephemerals via Curator > framework, they are created with with creatingParentsIfNeeded. The > whole tree disappears when the last ephemeral leaf node is removed. > Parent nodes have an IP address as value. > > > Code snip from our class: > > CreateModable<ACLBackgroundPathAndBytesable<String>> localCreateMethod > = createMethod.get(); > if (localCreateMethod == null) { > CreateBuilderMain createBuilder = cfClient.create(); > CreateModable<ACLBackgroundPathAndBytesable<String>> > tempCreateMethod = createBuilder.creatingParentContainersIfNeeded(); > createMethod.compareAndSet(null, tempCreateMethod); > localCreateMethod = createMethod.get(); > } > > try { > localCreateMethod.withMode(CreateMode.EPHEMERAL).inBackground(backgroundCallback).forPath(basePath, > getEncryptedBytes(commandNode.getNodeBytes())); > } catch (Exception e) { > log.error("Exception: ", e); > } > > > > [zk: localhost:2181(CONNECTED) 1] get /GROUP_V7POC03/ephemerals/inquirylock > 10.194.54.93 > [zk: localhost:2181(CONNECTED) 2] stat > /GROUP_V7POC03/ephemerals/inquirylock > cZxid = 0xf20001914e > ctime = Tue Feb 04 11:11:45 CET 2020 > mZxid = 0xf200019169 > mtime = Tue Feb 04 11:11:48 CET 2020 > pZxid = 0xf20001918b > cversion = 2 > dataVersion = 3 > aclVersion = 0 > ephemeralOwner = 0x0 > dataLength = 12 > numChildren = 2 > [zk: localhost:2181(CONNECTED) 3] get /GROUP_V7POC03/ephemerals/inquirylock > 10.194.54.93 > [zk: localhost:2181(CONNECTED) 4] get /GROUP_V7POC03/ephemerals > > [zk: localhost:2181(CONNECTED) 5] stat > /GROUP_V7POC03/ephemerals/inquirylock/lrv1705f.europe.intranet:v7poc03 > cZxid = 0xf200019189 > ctime = Tue Feb 04 11:11:51 CET 2020 > mZxid = 0xf200019189 > mtime = Tue Feb 04 11:11:51 CET 2020 > pZxid = 0xf200019189 > cversion = 0 > dataVersion = 0 > aclVersion = 0 > ephemeralOwner = 0x10022c4e19c000b > dataLength = 83 > numChildren = 0 > > > > On 4 February 2020 15:58:39 Jordan Zimmerman <jor...@jordanzimmerman.com> > wrote: > > >> can I implement a lock recipe which just > >> tries to create ephemeral node without any persistent nodes. > > > > Ephemeral nodes cannot have any children. Unless you create your lock at > > the root ("/") you'd need some parent persistent node. Is this a big > > problem for you? Unless you have 1000s of unique lock paths there > shouldn't > > be any problem with persistent parent node. > > > > -Jordan >
