[jira] [Resolved] (CASSANDRA-5972) Reduce the amount of data to be transferred during repair

["Sylvain Lebresne (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CASSANDRA-5972?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Sylvain Lebresne resolved CASSANDRA-5972.
-----------------------------------------

    Resolution: Duplicate

This is basically a duplicate of CASSANDRA-3200. Long story short, last time I checked, doing this properly was a pain to do given the current code of repair. That being said, it's definitively possible and if you plan on spending time on this to make it happen, feel free to re-open CASSANDRA-3200 and assign yourself.
                
> Reduce the amount of data to be transferred during repair
> ---------------------------------------------------------
>
>                 Key: CASSANDRA-5972
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-5972
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>            Reporter: Jacek Lewandowski
>            Priority: Minor
>
> Currently, when a validator finds a token range different in n replicas, data streams are initiated simultaneously between each possible pair of these n nodes, in both directions. It yields n*(n-1) data stream in total. 
> It can be done in a sequence - R(1) -> R(2), R(2) -> R(3), ... , R(n-1) -> R(n). After this process, the data in R(n) are up to date. Then, we continue: R(n) -> R(1), R(1) -> R(2), ... , R(n-2) -> R(n-1). The active repair is done after 2*(n-1) data transfers performed sequentially in 2*(n-1) steps.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira