Thanks Robert!!

The JIRA was very helpful in understanding how tombstone threshold is 
implemented. And ticket also says that running major compaction weekly is an 
alternative. I actually want to understand if I run major compaction on a cf 
with 500gb of data and a single giant file is created. Do you see any problems 
with Cassandra processing such a huge file?  Is there any Max sstable size 
beyond which performance etc degrades? What are the implications?



Thanks

Anuj Wadehra

Sent from Yahoo Mail on Android

From:"Robert Coli" <rc...@eventbrite.com>
Date:Fri, 17 Apr, 2015 at 10:55 pm
Subject:Re: Drawbacks of Major Compaction now that Automatic Tombstone 
Compaction Exists

On Tue, Apr 14, 2015 at 8:29 PM, Anuj Wadehra <anujw_2...@yahoo.co.in> wrote:

By automatic tombstone compaction, I am referring to tombstone_threshold sub 
property under compaction strategy in CQL. It is 0.2 by default. So what I 
understand from the Datastax documentation is that even if a sstable does not 
find sstables of similar size (STCS) , an automatic tombstone compaction will 
trigger on sstable when 20% data is tombstone. This compaction works on single 
sstable only.


Overall system behavior is discussed here :


https://issues.apache.org/jira/browse/CASSANDRA-6654?focusedCommentId=13914587&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13914587


They are talking about LCS, but the principles apply, but with an overlay of 
how STS behaves.


=Rob


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