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https://issues.apache.org/jira/browse/CASSANDRA-6506?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13944567#comment-13944567
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Aleksey Yeschenko commented on CASSANDRA-6506:
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Any objections to at least committing the first two cleanup commits now (the
first one is there to mostly kill all the IDEA warnings, at last, but the
second one - c503d6ae89651186b9ac7fc8026eab0ace137af - does deconfuse the API a
bit) ?
> counters++ split counter context shards into separate cells
> -----------------------------------------------------------
>
> Key: CASSANDRA-6506
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6506
> Project: Cassandra
> Issue Type: Improvement
> Reporter: Aleksey Yeschenko
> Assignee: Aleksey Yeschenko
> Fix For: 2.1 beta2
>
>
> This change is related to, but somewhat orthogonal to CASSANDRA-6504.
> Currently all the shard tuples for a given counter cell are packed, in sorted
> order, in one binary blob. Thus reconciling N counter cells requires
> allocating a new byte buffer capable of holding the union of the two
> context's shards N-1 times.
> For writes, in post CASSANDRA-6504 world, it also means reading more data
> than we have to (the complete context, when all we need is the local node's
> global shard).
> Splitting the context into separate cells, one cell per shard, will help to
> improve this. We did a similar thing with super columns for CASSANDRA-3237.
> Incidentally, doing this split is now possible thanks to CASSANDRA-3237.
> Doing this would also simplify counter reconciliation logic. Getting rid of
> old contexts altogether can be done trivially with upgradesstables.
> In fact, we should be able to put the logical clock into the cell's
> timestamp, and use regular Cell-s and regular Cell reconcile() logic for the
> shards, especially once we get rid of the local/remote shards some time in
> the future (until then we still have to differentiate between
> global/remote/local shards and their priority rules).
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