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https://issues.apache.org/jira/browse/CASSANDRA-13066?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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ZhaoYang updated CASSANDRA-13066:
---------------------------------
    Component/s: Streaming and Messaging
                 Materialized Views

> Fast streaming with materialized views
> --------------------------------------
>
>                 Key: CASSANDRA-13066
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-13066
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Materialized Views, Streaming and Messaging
>            Reporter: Benjamin Roth
>            Assignee: Benjamin Roth
>             Fix For: 4.0
>
>
> I propose adding a configuration option to send streams of tables with MVs 
> not through the regular write path.
> This may be either a global option or better a CF option.
> Background:
> A repair of a CF with an MV that is much out of sync creates many streams. 
> These streams all go through the regular write path to assert local 
> consistency of the MV. This again causes a read before write for every single 
> mutation which again puts a lot of pressure on the node - much more than 
> simply streaming the SSTable down.
> In some cases this can be avoided. Instead of only repairing the base table, 
> all base + mv tables would have to be repaired. But this can break eventual 
> consistency between base table and MV. The proposed behaviour is always safe, 
> when having append-only MVs. It also works when using CL_QUORUM writes but it 
> cannot be absolutely guaranteed, that a quorum write is applied atomically, 
> so this can also lead to inconsistencies, if a quorum write is started but 
> one node dies in the middle of a request.
> So, this proposal can help a lot in some situations but also can break 
> consistency in others. That's why it should be left upon the operator if that 
> behaviour is appropriate for individual use cases.
> This issue came up here:
> https://issues.apache.org/jira/browse/CASSANDRA-12888?focusedCommentId=15736599&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15736599



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