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https://issues.apache.org/jira/browse/CASSANDRA-1546?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12922883#action_12922883
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Sylvain Lebresne commented on CASSANDRA-1546:
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bq. The limitation is during RESTORE_REPLICA_COUNT or BOOTSTRAP where a node
that was previously in the replica set becomes part of the replica set, again.
In this case, when CCs are streamed back to the, now re-added, host replica, it
will discard those CCs that it should treat as LCCs.
As you said, I think it is fine because of the fact the patches now use UUID as
node ids. The idea is that you'll never add back someone with
the same node id ever. That is, if you boostrap a node, it'll affect a brand
new, different from every previously assigned node id (and maybe boostrap
should just start to remove the node id from the system table if it exists to
force this regeneration).
If you add back a node previously removed, either the node still has its old
sstables (and so, for his node id, he has the correct count), and thus
you can add it back safely. Or you just force regenerating a new node id.
So I believe that it means that whenever you lose a sstable on a given node
(for any reason), you'll regenerate the node id. Now of course we
should be careful to not regenerate the node id too often because it'll make
the counter 'grow'. But I doubt it will be a problem.
bq. Another note on #1546, the digest creation for CC and LCC do not create the
same hashes.
True, that's the last bullet on my todo list (but my todo list may be lacking
bullets). My plan is to special case the digest creation indeed.
> (Yet another) approach to counting
> ----------------------------------
>
> Key: CASSANDRA-1546
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1546
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Reporter: Sylvain Lebresne
> Assignee: Sylvain Lebresne
> Fix For: 0.7.1
>
> Attachments: 0001-v2-Remove-IClock-from-internals.patch,
> 0001-v3-Remove-IClock-from-internals.txt, 0001-v4-Counters.patch,
> 0002-v2-Counters.patch, 0002-v3-Counters.txt, 0002-v4-thrift-changes.patch,
> 0003-v2-Thrift-changes.patch, 0003-v3-Thrift-changes.txt, marker_idea.txt
>
>
> This could be described as a mix between CASSANDRA-1072 without clocks and
> CASSANDRA-1421.
> More details in the comment below.
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