Mahadev Konar wrote:
Hi Nitay,
>
- Does this event happening mean my ephemeral nodes will go away?
No. the client will try connecting to other servers and if its not able to
reconnect to the servers within the remaining session timeout.

If the client is not able to connect within the remaining session timeout,
the session will expire and you will get a session expired event.

Isn't it the case that the client won't get session expired until it's able to connect to a server, right? So what might happen is that the client loses connection to the server, the server eventually expires the client and deletes ephemerals (notifying all watchers) but the client won't see the "session expiration" until it is able to reconnect to one of the servers. ie the client doesn't know it's been expired until it's able to reconnect to the cluster, at which point it's notified that it's been expired.

http://hadoop.apache.org/zookeeper/docs/r3.0.1/zookeeperProgrammers.html
Has this information scattered around, but we should put it in the FAQ
specifically.

3.0.1 is a bit old, try this for the latest docs:
http://hadoop.apache.org/zookeeper/docs/current/zookeeperProgrammers.html

- Is the ZooKeeper handle I'm using dead after this event?
Again no. your handle is valid until you get an session expiry event or you
do a zoo_close on your handle.


Thanks mahadev




On 3/25/09 5:42 PM, "Nitay" <nit...@gmail.com> wrote:

I'm a little unclear about the ConnectionLoss exception as it's described in
the FAQ and would like some clarification.

From the state diagram, http://wiki.apache.org/hadoop/ZooKeeper/FAQ#1, there
are three events that cause a ConnectionLoss:

1) In Connecting state, call close().
2) In Connected state, call close().
3) In Connected state, get disconnected.

It's the third one I'm unclear about.

- Does this event happening mean my ephemeral nodes will go away?
- Is the ZooKeeper handle I'm using dead after this event? Meaning that,
similar to the SessionExpired case, I need to construct a new connection
handle to ZooKeeper and take care of the restarting myself. It seems from
the diagram that this should not be the case. Rather, seeing as the
disconnected event sends the user back to the Connecting state, my handle
should be fine and the library will keep trying to reconnect to ZooKeeper
internally? I understand my current operation may have failed, what I'm
asking about is future operations.

Thanks,
-n

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