[ 
https://issues.apache.org/jira/browse/CASSANDRA-13664?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16076030#comment-16076030
 ] 

Marcus Eriksson commented on CASSANDRA-13664:
---------------------------------------------

bq. isn't the issue here that the streams aren't weighted
Yes, that would be a nicer solution. It wasn't obvious to me how to do maximum 
bipartite matching with weighted edges though so I went with the easy solution 
(I guess having an edge for each token would be a way, but that would be quite 
silly). Also have to say I didn't spend very much time trying to figure it out, 
so if you have an idea, please let me know.

> RangeFetchMapCalculator should not try to optimise 'trivial' ranges
> -------------------------------------------------------------------
>
>                 Key: CASSANDRA-13664
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-13664
>             Project: Cassandra
>          Issue Type: Bug
>            Reporter: Marcus Eriksson
>            Assignee: Marcus Eriksson
>             Fix For: 4.x
>
>
> RangeFetchMapCalculator (CASSANDRA-4650) tries to make the number of streams 
> out of each node as even as possible.
> In a typical multi-dc ring the nodes in the dcs are setup using token + 1, 
> creating many tiny ranges. If we only try to optimise over the number of 
> streams, it is likely that the amount of data streamed out of each node is 
> unbalanced.
> We should ignore those trivial ranges and only optimise the big ones, then 
> share the tiny ones over the nodes.



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org
For additional commands, e-mail: commits-h...@cassandra.apache.org

Reply via email to