JEP 173: Remove Rarely-Used Combinations of Garbage Collectors

Srinivas Ramakrishna ysr1729 at gmail.com
Wed Dec 5 15:01:05 PST 2012


Hi Kirk --

On Wed, Dec 5, 2012 at 2:48 PM, Kirk Pepperdine <kirk at kodewerk.com> wrote:

> Hi all,
>
>
> The JEP's are coming in fast and furious. There is a customer use case for
> iCMS.. it's used by low latency applications... and quite successfully in
> fact. iCMS manages large heaps much better than CMS does which translates
> into more manageable pause times... I've got logs from a number of
> customers that rely on iCMS.
>

This is very interesting indeed (and something i had vaguely heard a few
years ago from the general grapevine, although never actually understood
why it must be so). Could you go a bit deeper on why this is so? What
exactly is it about doing a "slow, spread-out, incremental CMS collection"
that makes it work better than bang-bang vanilla CMS in large multi-core,
server environments? Perhaps the insights from that might translate into
something useful for vanilla CMS?

Your experience does indicate that we must proceed with some caution here
before we deprecate iCMS, given it might still have some useful life
(notwithstanding my own instincts to the contrary -- in server environments
-- expressed in an earlier email before I had seen yours).

thanks.
-- ramki


> Regards,
> Kirk
>
>
> On 2012-12-05, at 11:10 PM, mark.reinhold at oracle.com wrote:
>
> > Posted: http://openjdk.java.net/jeps/173
> >
> > - Mark
>
>
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