[ 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-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org