issues after porting a mac app from Java 6 to 7u9

[Srinivas Ramakrishna]

Correction inline below:

On Tue, Nov 13, 2012 at 1:23 AM, Srinivas Ramakrishna <ysr1729 at gmail.com>wrote:

>
>
> On Mon, Nov 12, 2012 at 6:54 AM, Rick Hillegas <rick.hillegas at oracle.com>wrote:
>
>> ...
>>
>> 2) The other problem is probably too vague, but here goes: I seem to have
>> memory management issues. After running the app for a while, it starts
>> freezing up and I watch the beachball spin. Eventually the app becomes
>> unusable and I have to re-start it. Is it expected that I will need to give
>> an app more memory in order to run it on Java 7?
>>
>>
> The default GC with JDK 6 on the Mac was -XX:+UseConcMarkSweepGC. With JDK
> 7 it is -XX:+UseParallelGC.
>

Actually -XX:+UseParallelOldGC (not just -XX:+UseParallelGC).

-- ramki


> I suspect the JDK 6 version that was the default on your mac, also used a
> different default heap size.
> The combination of a different heap size and a different collector (but
> especially a different heap size)
> could make  a big difference in performance (especially if you were
> running lots of other stuff on your
> mac, so that the Java heap was paging during full gc).
>
> As others have indicated, verbose gc logs are your friend.
> -- ramki
>