[ 
https://issues.apache.org/jira/browse/CASSANDRA-4310?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13396814#comment-13396814
 ] 

Jonathan Ellis commented on CASSANDRA-4310:
-------------------------------------------

That would be a good improvement to make.
                
> Multiple independent Level Compactions in Parallel(Useful for SSD). 
> --------------------------------------------------------------------
>
>                 Key: CASSANDRA-4310
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-4310
>             Project: Cassandra
>          Issue Type: New Feature
>          Components: Core
>    Affects Versions: 1.1.1, 1.1.2
>            Reporter: sankalp kohli
>              Labels: compaction, features, leveled, performance, ssd
>
> Problem: If you are inserting data into cassandra and level compaction cannot 
> catchup, you will create lot of files in L0.  
> Here is a solution which will help here and also increase the performance of 
> level compaction.
> We can do many compactions in parallel for unrelated data.
> 1) For no over lapping levels. Ex: when L0 stable is compacting with L1, we 
> can do compactions in other levels like L2 and L3 if they are eligible.
> 2) We can also do compactions with files in L1 which are not participating in 
> L0 compactions.
> This is specially useful if you are using SSD and is not bottlenecked by IO. 
> I am seeing this issue in my cluster. The compactions pending are more than 
> 50k and the disk usage is not that much(I am using SSD).
> I am doing multithreaded to true and also not throttling the IO by putting 
> the value as 0. 
>  

--
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

        

Reply via email to