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https://issues.apache.org/jira/browse/CASSANDRA-7486?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14523630#comment-14523630
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Ariel Weisberg commented on CASSANDRA-7486:
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bq. ^ G1 doesn't work that way.
I am talking about CMS. When I looked at the 12 gigabyte heap the old gen grew
to 4.1 gigabytes and I didn't see any point that it shrunk.
bq. I'm spending all of my time tuning users' clusters where the #1 first
issue every time is getting CMS to behave.
We can make the case for G1 in different ways. If we want to do it based on
real world results that is fine with me.
To Benedict's point I think looking at all the operations we care about on
realistic time scales is something we would have to do to really know what the
differences are. I wish we had this stuff in CI so it would just be a matter of
changing the flags, but we aren't there yet.
> Compare CMS and G1 pause times
> ------------------------------
>
> Key: CASSANDRA-7486
> URL: https://issues.apache.org/jira/browse/CASSANDRA-7486
> Project: Cassandra
> Issue Type: Test
> Components: Config
> Reporter: Jonathan Ellis
> Assignee: Shawn Kumar
> Fix For: 2.1.x
>
>
> See
> http://www.slideshare.net/MonicaBeckwith/garbage-first-garbage-collector-g1-7486gc-migration-to-expectations-and-advanced-tuning
> and https://twitter.com/rbranson/status/482113561431265281
> May want to default 2.1 to G1.
> 2.1 is a different animal from 2.0 after moving most of memtables off heap.
> Suspect this will help G1 even more than CMS. (NB this is off by default but
> needs to be part of the test.)
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