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https://issues.apache.org/jira/browse/CASSANDRA-2045?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13057419#comment-13057419
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Jonathan Ellis commented on CASSANDRA-2045:
-------------------------------------------

bq. losing hints during upgrade isn't the end of the world

Right.  I'm saying we should do this:

Hints: {                    // cf
  <dest ip>: {              // key
    <key>: {                // super-column
      <table>-<cf>: <id>    // column
      mutation: <mutation>  // column
    }
  }
}

So we denormalize but we gain not having to do secondary-lookup-per-mutation, 
which is our main motivation for the change.  (And single-destination-per-hint 
is by far the common case.)

bq. Can we open this as a dependent ticket?

WFM.

> Simplify HH to decrease read load when nodes come back
> ------------------------------------------------------
>
>                 Key: CASSANDRA-2045
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-2045
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Chris Goffinet
>            Assignee: Nicholas Telford
>             Fix For: 1.0
>
>         Attachments: 
> 0001-Changed-storage-of-Hints-to-store-a-serialized-RowMu.patch, 
> 0002-Refactored-HintedHandoffManager.sendRow-to-reduce-co.patch, 
> 0003-Fixed-some-coding-style-issues.patch, 
> 0004-Fixed-direct-usage-of-Gossiper.getEndpointStateForEn.patch, 
> 0005-Removed-duplicate-failure-detection-conditionals.-It.patch, 
> 0006-Removed-handling-of-old-style-hints.patch, 2045-v3.txt, 
> CASSANDRA-2045-simplify-hinted-handoff-001.diff, 
> CASSANDRA-2045-simplify-hinted-handoff-002.diff
>
>
> Currently when HH is enabled, hints are stored, and when a node comes back, 
> we begin sending that node data. We do a lookup on the local node for the row 
> to send. To help reduce read load (if a node is offline for long period of 
> time) we should store the data we want forward the node locally instead. We 
> wouldn't have to do any lookups, just take byte[] and send to the destination.

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