zookeeper-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Eason Liao <liaoyishen...@gmail.com>
Subject Re: How does Zookeeper handle this situation
Date Mon, 10 Nov 2014 10:45:25 GMT
Here data means the transactions in log, not the data in ZooKeeper's
in-memory tree structure. The transaction must be committed first before
gets applied to ZooKeeper's in-memory state.

2014-11-10 2:41 GMT-08:00 Eason Liao <liaoyisheng89@gmail.com>:

> It's possible that D, E have more recent data, and the data of D, E will
> be discarded if they join leader. This is fine as long as the data is not
> COMMITTED.
>
> We consider the transaction is committed only if the transaction is
> persisted in the log of majority servers. In this case, if D, E have the
> committed data, then at least
> one of A, B, C will also have it. So the committed data won't get lost.
>
> Hope this answers your question.
>
>
>
> 2014-11-10 2:36 GMT-08:00 bit1129@163.com <bit1129@163.com>:
>
>
>> Hi zookeepers,
>>
>> I got a question about leader election during ensemble starts up.   Say,
>> I got five servers, ABCDE, and start them one by one.
>> According to the election algorithm, ABC forms the majority, and then a
>> leader is elected among ABC. When D, E start up, they will follow the
>> leader. What if D or E have more recent data among ABCDE?
>> D,E's latest data will simply be discard? If this is case, this is a
>> critical issue.
>>
>> Very likely that I missed something how leader election works during
>> startup, any explanation on this? thinks.
>>
>>
>>
>>
>> bit1129@163.com
>>
>
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message