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Date: Mon, 10 Oct 2016 14:07:21 +0000 (UTC)
From: "Paulo Motta (JIRA)" <jira@apache.org>
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Subject: [jira] [Commented] (CASSANDRA-12744) Randomness of stress
 distributions is not good
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archived-at: Mon, 10 Oct 2016 14:07:23 -0000


    [ https://issues.apache.org/jira/browse/CASSANDRA-12744?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15562403#comment-15562403 ] 

Paulo Motta commented on CASSANDRA-12744:
-----------------------------------------

some [cqlsh_copy_tests|http://cassci.datastax.com/job/tjake-stress-random-dtest/lastCompletedBuild/testReport/cqlsh_tests.cqlsh_copy_tests/] are outputting the following error:
{noformat}
cassandra-stress did not import enough records
{noformat}

do you think this could be related to the distribution change? if not, can you maybe rebase and resubmit those?

> Randomness of stress distributions is not good
> ----------------------------------------------
>
>                 Key: CASSANDRA-12744
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-12744
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Tools
>            Reporter: T Jake Luciani
>            Assignee: T Jake Luciani
>            Priority: Minor
>              Labels: stress
>             Fix For: 3.0.10
>
>
> The randomness of our distributions is pretty bad.  We are using the JDKRandomGenerator() but in testing of uniform(1..3) we see for 100 iterations it's only outputting 3.  If you bump it to 10k it hits all 3 values. 
> I made a change to just use the default commons math random generator and now see all 3 values for n=10


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