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From Flavio Junqueira <...@apache.org>
Subject Re: are ephemeral nodes removed when client receives session expiration
Date Thu, 26 Jan 2017 00:19:33 GMT
Hey Jun,

The way you're phrasing the question is problematic. Receiving a session expiration means
that a closeSession has been committed, so a quorum has seen the closeSession event. However,
a minority might still think the session is up, so if you ask whether the ephemerals are still
there at the "time" the client receives the session expiration event, then the answer is that
it depends on which server you're talking to, one of the majority or one of the minority.

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.

-Flavio


> On 25 Jan 2017, at 16:53, Jun Rao <junrao@gmail.com> wrote:
> 
> Hi,
> 
> Does ZK guarantee that ephemeral nodes from a client are removed on the
> sever by the time the client receives a session expiration event? I am
> getting conflicting info on this (
> https://issues.apache.org/jira/browse/KAFKA-4277). Could someone clarify?
> 
> Thanks,
> 
> Jun


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