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Zookeeper, mail # user - Question regarding ZK behaviour during leader reelection


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Question regarding ZK behaviour during leader reelection
yuliya Feldman 2012-01-05, 22:30
Hello here,

I have a question regarding ZK clients behaviour during ZK Leader reelection.

We have a situation where server where ZK Leader was running run low on memory and essentially ZK was "frozen" for quite a bit of time.

Meanwhile other 2 ZK servers did reelections among them and new Leader was chosen.

Now on ZK client nodes (not taking "bad" node into consideration) got Disconnect and Closely after Connect events, because as far as I understand no leader was available for about 500 ms. (during reelection).

The question really is - as it is very likely that it will be some time during ZK leader election when none of the ZK servers will be available ZK clients are very likely to "feel" that something happened on the ZK Server (Quorum side).
Which means that ANY application that relies on Zookeeper has to at least handle Disconnect event gracefully.

Are my assumptions correct?

Thanks.
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yuliya Feldman 2012-01-16, 18:28
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Camille Fournier 2012-01-16, 18:39
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yuliya Feldman 2012-01-16, 18:50