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https://issues.apache.org/jira/browse/CASSANDRA-1972?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12981903#action_12981903
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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.

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