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https://issues.apache.org/jira/browse/CASSANDRA-5569?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13658468#comment-13658468
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Rick Branson commented on CASSANDRA-5569:
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What I'm working with now is adding a second method signature with a "flush"
boolean that allows the behavior to be turned off for StreamingRepairTask.
> Every stream operation requires checking indexes in every SSTable
> -----------------------------------------------------------------
>
> Key: CASSANDRA-5569
> URL: https://issues.apache.org/jira/browse/CASSANDRA-5569
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Affects Versions: 1.2.0
> Reporter: Rick Branson
> Assignee: Rick Branson
> Priority: Minor
> Labels: streaming
> Fix For: 1.2.5
>
> Attachments: 5569.txt, 5569-v2.txt
>
>
> It looks like there's a streaming performance issue when leveled compaction
> and vnodes get together. To get the candidate set of chunks to stream, the
> streaming system gets references to every SSTable for a CF. This is probably
> a perfectly reasonable assumption for non-vnode cases, because the data being
> streamed is likely distributed across the full SSTable set. This is also
> probably a perfectly reasonable assumption for size-tiered compaction,
> because the data is, again, likely distributed across the full SSTable set.
> However, for each vnode repair performed on LCS CF's, this scan across
> potentially tens of thousands of SSTables is wasteful considering that only a
> small percentage of them will actually have data for a given range.
> This manifested itself as "hanging" repair operations with tasks backing up
> on the MiscStage thread pool.
> The attached patch changes the streaming code so that for a given range, only
> SSTables for the requested range are checked to be included in streaming.
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