[jira] [Commented] (CASSANDRA-8460) Make it possible to move non-compacting sstables to slow/big storage in DTCS

["stone (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-8460?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15354399#comment-15354399 ] 

stone commented on CASSANDRA-8460:
----------------------------------

there are several questions about this issue
1.from application perspective,we rarely used these arhived data,
but when scale up cluster,add node or decommission node,we will stream data between node,
since these archived sstable still in token ring,how to deal with these archived sstable.we need to 
access them,it may take long time to finish bootstrap when the arhived data is too large.

2.why not separate  "archive sstable" from compaction compaction strategy?
archive sstable is not a round,in-time task,we just need to execute the task periodly.
I mean there are high coupling between compaction and archiving data.
we can provide a sstable tool to archive data.split sstable by date is the job of compaction strategy.
we dont care it is DTCS or TWCS.

3.in ArchivingDateTieredCompactionWriter.java
we archive sstable with SSTableWriter.i just thought that why not use softlink.move sstable file,and create softlink.
actually I'm not clearly about how the sstable files are moved with the method of SSTableWriter.switchWriter().
I just saw cassandra backup data with hardlink,so we can use softlink to archive data.

> Make it possible to move non-compacting sstables to slow/big storage in DTCS
> ----------------------------------------------------------------------------
>
>                 Key: CASSANDRA-8460
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8460
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Marcus Eriksson
>              Labels: doc-impacting, dtcs
>             Fix For: 3.x
>
>
> It would be nice if we could configure DTCS to have a set of extra data directories where we move the sstables once they are older than max_sstable_age_days. 
> This would enable users to have a quick, small SSD for hot, new data, and big spinning disks for data that is rarely read and never compacted.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)