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From "Marcus Eriksson (JIRA)" <j...@apache.org>
Subject [jira] [Comment Edited] (CASSANDRA-11350) Max_SSTable_Age isn't really deprecated in DTCS
Date Mon, 14 Mar 2016 19:31:33 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-11350?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15193983#comment-15193983
] 

Marcus Eriksson edited comment on CASSANDRA-11350 at 3/14/16 7:30 PM:
----------------------------------------------------------------------

max_sstable_age_days is left at 1000 years, if someone wants to get the exact behaviour they
had before they can change it back

With those settings you will do compaction in 1day-sized windows until they are 1 year old.
But the thing is you will actually not do any compaction unless you have to (like after repair
etc) since the windows don't change, so keeping max_sstable_age_days at 1 year is quite pointless.

Problem with max_sstable_age_days is that. If you bootstrap a new node for example you can
end up with a huge amount of sstables older than max_sstable_age_days


was (Author: krummas):
max_sstable_age_days is left at 1000 years, if someone wants to get the exact behaviour they
had before

With those settings you will do compaction in 1day-sized windows until they are 1 year old.
But the thing is you will actually not do any compaction unless you have to (like after repair
etc) since the windows don't change, so keeping max_sstable_age_days at 1 year is quite pointless.

Problem with max_sstable_age_days is that. If you bootstrap a new node for example you can
end up with a huge amount of sstables older than max_sstable_age_days

> Max_SSTable_Age isn't really deprecated in DTCS
> -----------------------------------------------
>
>                 Key: CASSANDRA-11350
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-11350
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Compaction
>         Environment: PROD
>            Reporter: Anubhav Kale
>            Priority: Minor
>
> Based on the comments in https://issues.apache.org/jira/browse/CASSANDRA-10280, and changes
made to DateTieredCompactionStrategyOptions.java, the Max_SSTable_Age field is marked as deprecated.
> However, this is still used to filter the old SS Tables in DateTieredCompactionStrategy.java.
Once those tables are filtered, Max_Window_Size is used to limit how back in time we can go
(essentially how Max_SSTable_Age was used previously).
> So I am somewhat confused on the exact use of these two fields. Should Max_SSTable_Age
be really removed and Max_Window_Size be used to filter old tables (in which case it should
be set to 1 year as well) ?
> Currently, Max_SSTable_Age = 1 Year, and Max_Window_Size = 1 Day. What is the expected
behavior with these settings ?



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