cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jonathan Ellis (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-6078) Wrong memtable size estimation: liveRatio is not honored in edge cases
Date Tue, 24 Sep 2013 13:39:05 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-6078?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13776306#comment-13776306
] 

Jonathan Ellis commented on CASSANDRA-6078:
-------------------------------------------

WDYT [~jasobrown]?
                
> Wrong memtable size estimation: liveRatio is not honored in edge cases
> ----------------------------------------------------------------------
>
>                 Key: CASSANDRA-6078
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-6078
>             Project: Cassandra
>          Issue Type: Bug
>            Reporter: Oleg Anastasyev
>            Priority: Minor
>             Fix For: 1.2.11, 2.0.2
>
>         Attachments: 6078-v2.txt, Memtable-getLiveSize.diff
>
>
> Memtable.getLiveSize does not honours liveRatio the correct way: 
> allocator.get**Size() return sizes allocated only by name and columns data (i.e. no liveRatio
applied); but conditions, which cap estimated size, compare it with estimatedSize, already
multiplied by liveRatio.
> If liveRatio is big enough (i've seen >11 on our dataset), this leads to huge estimation
errors and even to OutOfMemory, because MeteredFlusher  underestimates memtables sizes.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message