[
https://issues.apache.org/jira/browse/CASSANDRA-6357?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jonathan Ellis updated CASSANDRA-6357:
--------------------------------------
Priority: Minor (was: Major)
Fix Version/s: 2.0.6
Issue Type: New Feature (was: Improvement)
> Flush memtables to separate directory
> -------------------------------------
>
> Key: CASSANDRA-6357
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6357
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Reporter: Patrick McFadin
> Assignee: Jonathan Ellis
> Priority: Minor
> Fix For: 2.0.6
>
> Attachments: 6357-v2.txt, 6357.txt,
> c6357-stress-write-latency-99th-1.png
>
>
> Flush writers are a critical element for keeping a node healthy. When several
> compactions run on systems with low performing data directories, IO becomes a
> premium. Once the disk subsystem is saturated, write IO is blocked which will
> cause flush writer threads to backup. Since memtables are large blocks of
> memory in the JVM, too much blocking can cause excessive GC over time
> degrading performance. In the worst case causing an OOM.
> Since compaction is running on the data directories. My proposal is to create
> a separate directory for flushing memtables. Potentially we can use the same
> methodology of keeping the commit log separate and minimize disk contention
> against the critical function of the flushwriter.
--
This message was sent by Atlassian JIRA
(v6.1.5#6160)
