[jira] [Commented] (CASSANDRA-3943) Too many small size sstables after loading data using sstableloader or BulkOutputFormat increases compaction time.

["Stu Hood (Commented) (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-3943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13235427#comment-13235427 ] 

Stu Hood commented on CASSANDRA-3943:
-------------------------------------

I'd like to work on this, as it seems like it should be possible to make a BulkOutputFormat that writes at most one sstable from each reducer to each host, if you sort the data by token before it arrives at the reducer. Essentially, the OutputFormat would assert that it was receiving the data in sorted order, and write it straight to the socket as an sstable data file: this has been the 'lifelong dream' of MapReduce integration.
                
> Too many small size sstables after loading data using sstableloader or BulkOutputFormat increases compaction time.
> ------------------------------------------------------------------------------------------------------------------
>
>                 Key: CASSANDRA-3943
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-3943
>             Project: Cassandra
>          Issue Type: Wish
>          Components: Hadoop, Tools
>    Affects Versions: 0.8.2, 1.1.0
>            Reporter: Samarth Gahire
>            Priority: Minor
>              Labels: bulkloader, hadoop, ponies, sstableloader, streaming, tools
>   Original Estimate: 168h
>  Remaining Estimate: 168h
>
> When we create sstables using SimpleUnsortedWriter or BulkOutputFormat,the size of sstables created is around the buffer size provided.
> But After loading , sstables created in the cluster nodes are of size around
> {code}( (sstable_size_before_loading) * replication_factor ) / No_Of_Nodes_In_Cluster{code}
> As the no of nodes in cluster goes increasing, size of each sstable loaded to cassandra node decreases.Such small size sstables take too much time to compact (minor compaction) as compare to relatively large size sstables.
> One solution that we have tried is to increase the buffer size while generating sstables.But as we increase the buffer size ,time taken to generate sstables increases.Is there any solution to this in existing versions or are you fixing this in future version?

--
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