cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jonathan Ellis (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-3262) SimpleSnitch.compareEndpoints doesn't respect the intent of the snitch
Date Tue, 27 Sep 2011 12:57:11 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-3262?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13115458#comment-13115458
] 

Jonathan Ellis commented on CASSANDRA-3262:
-------------------------------------------

The reason for this behavior (CASSANDRA-1314) is because for best performance, normal reads
want exactly the opposite behavior of counters: we want to direct reads to the same replica
so that the cache stays hot.  Put another way, if each replica is serving a distinct range
then you get (replica count) times as much cache memory [with CL.ONE and RR off) than if each
is getting the full range of requests from different coordinators.
                
> SimpleSnitch.compareEndpoints doesn't respect the intent of the snitch
> ----------------------------------------------------------------------
>
>                 Key: CASSANDRA-3262
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-3262
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>    Affects Versions: 0.8.6
>            Reporter: Sylvain Lebresne
>            Assignee: Sylvain Lebresne
>            Priority: Minor
>             Fix For: 0.8.7, 1.0.0
>
>         Attachments: 3262.patch
>
>
> SimpleSnitch is supposed to not sort the input addresses, thus respecting the order of
the partitioner. However, it's compareEndpoints instead uses IP addresses comparison. Note
that this matter when the dynamicSnitch fall back to the wrapped snitch since it uses the
compareEndpoint method then.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message