Rick Branson created CASSANDRA-5569:
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Summary: 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: 1.2.4
Reporter: Rick Branson
Assignee: Rick Branson
Fix For: 1.2.4
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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