[
https://issues.apache.org/jira/browse/CASSANDRA-1902?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
T Jake Luciani updated CASSANDRA-1902:
--------------------------------------
Remaining Estimate: 96h
Original Estimate: 96h
> Migrate cached pages during compaction
> ---------------------------------------
>
> Key: CASSANDRA-1902
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1902
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Affects Versions: 0.7.1
> Reporter: T Jake Luciani
> Assignee: T Jake Luciani
> Fix For: 0.7.1
>
> Original Estimate: 96h
> Remaining Estimate: 96h
>
> Post CASSANDRA-1470 there is an opportunity to migrate cached pages from a
> pre-compacted CF during the compaction process.
> First, add a method to MmappedSegmentFile: long[] pagesInPageCache() that
> uses the posix mincore() function to detect the offsets of pages for this
> file currently in page cache.
> Then add getActiveKeys() which uses underlying pagesInPageCache() to get the
> keys actually in the page cache.
> use getActiveKeys() to detect which SSTables being compacted are in the os
> cache and make sure the subsequent pages in the new compacted SSTable are
> kept in the page cache for these keys. This will minimize the impact of
> compacting a "hot" SSTable.
> A simpler yet similar approach is described here:
> http://insights.oetiker.ch/linux/fadvise/
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
