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https://issues.apache.org/jira/browse/CASSANDRA-1608?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Benjamin Coverston updated CASSANDRA-1608:
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Attachment: 2608-v6.txt
Added a patch with fixed range filters.
With ~1100 sstables average latency is substantially increased (~5-10x). I'm
pretty sure that in order to improve on this well need to implement an interval
tree to get a non-linear search time for overlapping sstables in interval
queries.
The problem here is that there aren't any really good RBtree or even binary
tree implementations that I have found in the dependencies that we currently
have, and I really don't want to muddy this ticket up with that effort.
There are some potentially useful structures in UIMA that I can use to base the
implementation of an interval tree off of, but right now I'm leaning toward
doing this in a separate ticket.
> Redesigned Compaction
> ---------------------
>
> Key: CASSANDRA-1608
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1608
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Chris Goffinet
> Assignee: Benjamin Coverston
> Attachments: 0001-leveldb-style-compaction.patch, 1608-v2.txt,
> 1608-v3.txt, 1608-v4.txt, 1608-v5.txt, 2608-v6.txt
>
>
> After seeing the I/O issues in CASSANDRA-1470, I've been doing some more
> thinking on this subject that I wanted to lay out.
> I propose we redo the concept of how compaction works in Cassandra. At the
> moment, compaction is kicked off based on a write access pattern, not read
> access pattern. In most cases, you want the opposite. You want to be able to
> track how well each SSTable is performing in the system. If we were to keep
> statistics in-memory of each SSTable, prioritize them based on most accessed,
> and bloom filter hit/miss ratios, we could intelligently group sstables that
> are being read most often and schedule them for compaction. We could also
> schedule lower priority maintenance on SSTable's not often accessed.
> I also propose we limit the size of each SSTable to a fix sized, that gives
> us the ability to better utilize our bloom filters in a predictable manner.
> At the moment after a certain size, the bloom filters become less reliable.
> This would also allow us to group data most accessed. Currently the size of
> an SSTable can grow to a point where large portions of the data might not
> actually be accessed as often.
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