[ 
https://issues.apache.org/jira/browse/CASSANDRA-3741?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13185742#comment-13185742
 ] 

Jonathan Ellis commented on CASSANDRA-3741:
-------------------------------------------

Thanks, Vitalii!

Unfortunately we can't use that patch as is because adding ops * 20 in there is 
going to throw off the size calculation for other workloads.

Note that the "throughput" size for a deletion is NOT zero (see Column.size 
implementation).  It sounds like you abruptly changed your workload from doing 
a bunch of larger inserts, then hit it with a ton of deletes all at once and 
OOMed before it was able to update its liveRatio estimate.

So the real problem is that if you change workloads dramatically enough, 
Cassandra's estimates can be off.
                
> OOMs because delete operations are not accounted
> ------------------------------------------------
>
>                 Key: CASSANDRA-3741
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-3741
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>    Affects Versions: 1.1
>         Environment: FreeBSD
>            Reporter: Vitalii Tymchyshyn
>
> Currently we are moving to new data format where new format is written into 
> new CFs and old one is deleted key-by-key. 
> I have started getting OOMs and found out that delete operations are not 
> accounted and so, column families are not flushed (changed == 0 with delete 
> only operations) by storage manager.
> This is pull request that fixed this problem for me: 
> https://github.com/apache/cassandra/pull/5

--
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