[
https://issues.apache.org/jira/browse/CASSANDRA-6506?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13938500#comment-13938500
]
Aleksey Yeschenko commented on CASSANDRA-6506:
----------------------------------------------
https://github.com/iamaleksey/cassandra/commits/6506
The branch is missing two things:
1. Filter conversion between 2.0 and 2.1 nodes (read compatibility) - I'm still
finishing it up/testing
2. sstableimport/sstableexport/ASSTSW support for new counter cells (trivial)
Extensive tests (unit and dtestes) will go into CASSANDRA-6626. I want this in
sooner than that.
[~slebresne] Can you start reviewing it as is? I'll push the two commits that
are left before you are done with the review of these.
> 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).
--
This message was sent by Atlassian JIRA
(v6.2#6252)
