Tom White wrote:
On Mon, May 18, 2009 at 11:44 AM, Steve Loughran <ste...@apache.org> wrote:
Grace wrote:
To follow up this question, I have also asked help on Jrockit forum. They
kindly offered some useful and detailed suggestions according to the JRA
results. After updating the option list, the performance did become better
to some extend. But it is still not comparable with the Sun JVM. Maybe, it
is due to the use case with short duration and different implementation in
JVM layer between Sun and Jrockit. I would like to be back to use Sun JVM
currently. Thanks all for your time and help.
what about flipping the switch that says "run tasks in the TT's own JVM?".
That should handle startup costs, and reduce the memory footprint
The property mapred.job.reuse.jvm.num.tasks allows you to set how many
tasks the JVM may be reused for (within a job), but it always runs in
a separate JVM to the tasktracker. (BTW
https://issues.apache.org/jira/browse/HADOOP-3675has some discussion
about running tasks in the tasktracker's JVM).
Tom
Tom,
that's why you are writing a book on Hadoop and I'm not ...you know the
answers and I have some vague misunderstandings,
-steve
(returning to the svn book)
