[
https://issues.apache.org/jira/browse/CASSANDRA-4310?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13473398#comment-13473398
]
Yuki Morishita commented on CASSANDRA-4310:
-------------------------------------------
bq. Is filtering out the L1 compacting correct? If they are promoted to L2 then
great, but if they are part of what is happening in L0 then you still get
overlaps
You are right. Since we don't know which sstable goes which level, I reverted
that part.
bq. You can use Predicates.in instead of an anonymous Predicate
Fixed.
Update here:
https://github.com/yukim/cassandra/commit/af8df59aedda3c99bd1249dbb86572b89c333117
> Multiple independent Level Compactions in Parallel
> --------------------------------------------------
>
> Key: CASSANDRA-4310
> URL: https://issues.apache.org/jira/browse/CASSANDRA-4310
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Affects Versions: 1.0.0
> Reporter: sankalp kohli
> Assignee: Yuki Morishita
> Labels: compaction, features, leveled, performance, ssd
> Fix For: 1.2.1
>
> Attachments: 4310.txt, 4310-v2.txt, 4310-v3.txt, 4310-v5.txt
>
>
> 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
For more information on JIRA, see: http://www.atlassian.com/software/jira
