[jira] [Updated] (CASSANDRA-12619) Improve JBOD throughput

["Jeremy Hanna (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CASSANDRA-12619?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Jeremy Hanna updated CASSANDRA-12619:
-------------------------------------
    Labels: jbod-aware-compaction performance  (was: performance)

> Improve JBOD throughput
> -----------------------
>
>                 Key: CASSANDRA-12619
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-12619
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Natale Galioto
>            Priority: Major
>              Labels: jbod-aware-compaction, performance
>             Fix For: 4.x
>
>
> Nodes with spinning disks have very limited throughputs during compactions. This is mainly due to [https://issues.apache.org/jira/browse/CASSANDRA-6696][CASSANDRA-6696] where each SSTable got "sticked" to one data directory only. In order to increase the performance during compactions, reads and writes should always happen on different directories, and a single data directory (for both reads or writes) should be used by no more than one compactor at time. The current throughput of a single spinning disk can get as low as 20MB/s due to r/w seeks penalties, but a compaction between two different spindles could easily get 100MB/s or more throughput. Since 6696 requires sstables to always be on the same data directory, even a compaction between two different data directory and then a "brutal" copy back to the "appropriate" directory could get an overall throughput of 50MB/s. Another option would be to let SStables "float" between two data directories only, and "switch" between them at every compaction.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscribe@cassandra.apache.org
For additional commands, e-mail: commits-help@cassandra.apache.org