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From Steve Loughran <ste...@apache.org>
Subject Re: Sun JVM 1.6.0u18
Date Tue, 02 Mar 2010 10:23:12 GMT
Allen Wittenauer wrote:
> On 3/1/10 7:24 AM, "Edward Capriolo" <edlinuxguru@gmail.com> wrote:
>> u14 added support for the 64bit compressed memory pointers which
>> seemed important due to the fact that hadoop can be memory hungry. u15
>> has been stable in our deployments. Not saying you should not go
>> newer, but I would not go older then u14.
> How are the compressed memory pointers working for you?  I've been debating
> turning them on here, so real world experience would be useful from those
> that have taken plunge.

I used JRockit for a long time, which had compressed on for ages. Some 
Hadoop problems, filed as bugreps. One of the funniest is that JRockit 
stacks can get way bigger than JVM stacks, so some functional tests of 
mine that recursed and expected to OOM instead timed out.

On the Sun JVMS, not used them at "datacentre scale" but found memory 
savings in everything from IDEs up.

It'd be nice if there was an easy way to turn it on as default for 
everything, no faffing around with app-specific ops

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