[ https://issues.apache.org/jira/browse/CASSANDRA-8342?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
C. Scott Andreas updated CASSANDRA-8342: ---------------------------------------- Component/s: Documentation and Website > Remove historical guidance for concurrent reader and writer tunings. > -------------------------------------------------------------------- > > Key: CASSANDRA-8342 > URL: https://issues.apache.org/jira/browse/CASSANDRA-8342 > Project: Cassandra > Issue Type: Improvement > Components: Documentation and Website > Reporter: Matt Stump > Priority: Major > > The cassandra.yaml and documentation provide guidance on tuning concurrent > readers or concurrent writers to system resources (cores, spindles). Testing > performed by both myself and customers demonstrates no benefit for thread > pool sizes above 64 in size, and for thread pools greater than 128 in size a > decrease in throughput. This is due to thread scheduling and synchronization > bottlenecks within Cassandra. > Additionally, for lower end systems reducing these thread pools provides very > little benefit because the bottleneck is typically moved to either IO or CPU. > I propose that we set the default value to 64 (current default is 32), and > remove all guidance/recommendations regarding tuning. > This recommendation may change in 3.0, but that would require further > experimentation. -- 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