Hi folks, I was interested in the ephemeral node guarantees provided by ZooKeeper when a client reconnects after a session expiry event and stumbled across this discussion from 2017: https://www.mail-archive.com/user@zookeeper.apache.org/msg07578.html, which posed the exact question I was interested in:
"Does ZK guarantee that ephemeral nodes from a client are removed on the server by the time the client receives a session expiration event?" The conclusion of the thread was that, indeed, if a client receives a session expiry event and then reconnects to ZooKeeper, it should *not* see any of the ephemeral nodes created during the previous session: "If you ask whether the client will see its ephemerals upon creating a new session, then the answer is that it shouldn't because the createSession txn will be ordered necessarily before the closeSession txn, which implies that the client should not see the ephemerals." However, this leads me to today's question: does the answer above still hold if local sessions are enabled? Consider the following sequence of events, where the ZooKeeper cluster has *localSessionsEnabled* and *localSessionsUpgradingEnabled* on: (1) Client A creates an ephemeral node with path */foo/bar/baz* (2) Client A receives a session expiry event (3) Client A creates a new ZK session (4) Client A calls *exists()* for */foo/bar/baz *(the path of the ephemeral node created in step 1) Based on the original answer (when local sessions did not exist in ZooKeeper), client A will never see a non-null value in (4). My question is: does this property still hold if local sessions are enabled? Thanks, Shakeel
