[jira] [Commented] (ACCUMULO-2357) Document StatsIterator

["Keith Turner (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ACCUMULO-2357?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13899246#comment-13899246 ] 

Keith Turner commented on ACCUMULO-2357:
----------------------------------------

I have seen measurable performance impacts when accessing AtomicLongs  too often.  I think in this case I was trying to avoid this.  Incrementing the non-volatile can possibly be done in cache or in a register.  Incrementing the volitale has to go to main memory and may cause a cache flush. 

I think I just pulled 23 out of thin air, not sure if its too low.  I don't think I did performance testing to pick the number.  

> Document StatsIterator
> ----------------------
>
>                 Key: ACCUMULO-2357
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-2357
>             Project: Accumulo
>          Issue Type: Task
>            Reporter: Vikram Srivastava
>            Priority: Minor
>
> In particular it's not clear why it resets numRead to zero in {{next()}} after it reaches 23.



--
This message was sent by Atlassian JIRA
(v6.1.5#6160)