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https://issues.apache.org/jira/browse/CASSANDRA-8523?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15399949#comment-15399949
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Richard Low commented on CASSANDRA-8523:
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I'll review the 3.9 version. I'm very much in favour of putting this in 2.2 and 
3.0 as this hurts us badly and no doubt others suffer too.

> Writes should be sent to a replacement node while it is streaming in data
> -------------------------------------------------------------------------
>
>                 Key: CASSANDRA-8523
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8523
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Richard Wagner
>            Assignee: Paulo Motta
>             Fix For: 2.1.x
>
>
> In our operations, we make heavy use of replace_address (or 
> replace_address_first_boot) in order to replace broken nodes. We now realize 
> that writes are not sent to the replacement nodes while they are in hibernate 
> state and streaming in data. This runs counter to what our expectations were, 
> especially since we know that writes ARE sent to nodes when they are 
> bootstrapped into the ring.
> It seems like cassandra should arrange to send writes to a node that is in 
> the process of replacing another node, just like it does for a nodes that are 
> bootstraping. I hesitate to phrase this as "we should send writes to a node 
> in hibernate" because the concept of hibernate may be useful in other 
> contexts, as per CASSANDRA-8336. Maybe a new state is needed here?
> Among other things, the fact that we don't get writes during this period 
> makes subsequent repairs more expensive, proportional to the number of writes 
> that we miss (and depending on the amount of data that needs to be streamed 
> during replacement and the time it may take to rebuild secondary indexes, we 
> could miss many many hours worth of writes). It also leaves us more exposed 
> to consistency violations.



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