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Hudson commented on CASSANDRA-1972: ----------------------------------- Integrated in Cassandra-0.7 #157 (See [https://hudson.apache.org/hudson/job/Cassandra-0.7/157/]) update concurrent_reads default setting + comments patch by Stu Hood; reviewed by jbellis for CASSANDRA-1972 > Default concurrency values are improperly proportioned > ------------------------------------------------------ > > Key: CASSANDRA-1972 > URL: https://issues.apache.org/jira/browse/CASSANDRA-1972 > Project: Cassandra > Issue Type: Bug > Reporter: Stu Hood > Assignee: Stu Hood > Priority: Minor > Fix For: 0.7.1 > > Attachments: 0001-Recommendation-changes.txt > > > The "default"/"suggested" {{concurrent_reads}} value is much too low. It > assumes that CPU will be the bottleneck, rather than IO, and for most > deployments, this will not be the case. Additionally it is better to be > queued for IO in the kernel or on your device than in user space, because the > former work to optimize queue order. > Additionally, reads are much cheaper than writes in terms of CPU time (since > writes can experience contention due to retries), so while > {{concurrent_writes}} should probably factor in the number of cores on the > machine, {{concurrent_reads}} should probably be calculated purely by number > of spindles. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.