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Zookeeper, mail # user - Do we need a 'sync' to make sure no stale ephemeral nodes observed (created by exipred session)


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RE: Do we need a 'sync' to make sure no stale ephemeral nodes observed (created by exipred session)
Flavio Junqueira 2013-07-02, 16:54
Hi ChuChao,

I'm not entirely sure I understand the question, so please send some more
info if this is not the answer you're looking for. In general you don't have
to sync because the events are delivered in order, including the
notifications for say deleted znodes due to session expiration. An exception
to this rule is the case in which two clients talk directly to each other
and a client needs to make sure that it doesn't read a stale version
compared to the other client. But, this is not the case for you, then you
don't need to sync, just watch for the znode being deleted and react
accordingly when you receive the notification.

-Flavio

-----Original Message-----
From: chao chu [mailto:[EMAIL PROTECTED]]
Sent: 02 July 2013 17:44
To: [EMAIL PROTECTED]
Subject: Do we need a 'sync' to make sure no stale ephemeral nodes observed
(created by exipred session)

we know that for some performance reasons, different clients may have
slightly different views of znodes, for example, if client A updated node a,
and it let client B to read the node a, client B might still read the old
data and it need a 'sync' to see the latest.

Do we need to do the same thing when we concern about reading some stale
ephemeral nodes which are created by some already expired session?

Thanks & Regards,

--
ChuChao