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List:       cassandra-dev
Subject:    Re: G1GC is now default
From:       Jason Brown <jasedbrown () gmail ! com>
Date:       2018-08-10 17:46:24
Message-ID: CAHjqPuLR0+HA9v78O1YuRJX_37vgbYkemCOvvcnzS8QYUG0C-A () mail ! gmail ! com
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restored CMS as the default GC alg in CASSANDRA-14636.

Thanks,

-Jason

On Wed, Aug 8, 2018 at 4:33 PM, Jason Brown <jasedbrown@gmail.com> wrote:

> Hi Jon,
>
> Thanks for pointing that out. Looks like I missed that during the
> CASSANDRA-9608 review. Robert and I didn't discuss that online or offline,
> so it's something that snuck in.
>
> I don't have a personal preference for GC algs right now, but at a minimum
> it would probably be appropriate to return to CMS. We can certainly have a
> discussion thread about switching the default, but until we have that that,
> I think it's more honest to revert to CMS. If there's no immediate push
> back on reverting, I'll have a patch within a day to revert.
>
> Thanks,
>
> -Jason
>
> On Wed, Aug 8, 2018 at 3:34 PM, Jonathan Haddad <jon@jonhaddad.com> wrote:
>
>> I fired up trunk to check something, and noticed this:
>>
>> INFO  [Service Thread] 2018-08-08 15:01:36,723 GCInspector.java:290 - G1
>> Young Generation GC in 339ms.  G1 Eden Space: 4634705920 -> 0; G1 Old Gen:
>> 1190138352 -> 1435504616; G1 Survivor Space: 406847488 -> 301989888;
>>
>> which I thought was a bit weird, since I was using trunk without making
>> any
>> changes and didn't remember seeing a JIRA where we agreed to make that
>> change.  I looked back and saw it made it in as a side effect of
>> CASSANDRA-9608, but wasn't explicitly discussed in the ticket, and there's
>> no note of it in CHANGES.
>>
>> I'm personally OK with this change as G1 is a safer bet for anyone who
>> uses
>> the defaults, but we should be explicit about the change.  Can anyone
>> think
>> of a reason why we'd need to revert this back to ParNew / CMS?
>>
>> --
>> Jon Haddad
>> http://www.rustyrazorblade.com
>> twitter: rustyrazorblade
>>
>
>


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