On Feb 8, 2011, at 12:56 PM, Arun C Murthy wrote:
As Allen mentioned it's really hard for anyone here to help you with
CDH. You'll have to ask their user lists.
OTOH, there are significant enhancements we've done to the JobTracker
in 0.21 and 0.22... the problem is that there isn't an Apache release
yet.
the JT we run at Y! has a *huge* number of fixes for memory and
performance (>100% improvement) which we've started putting into a
0.20.100 branch - you might be interested in using that if you want a
packaged release: http://people.apache.org/~acmurthy/hadoop-0.20.100-rc0/
I should point out that this isn't an 'Apache Release', just something
for you to try if you are interested.
Arun
Arun
On Feb 8, 2011, at 8:59 AM, Maxim Zizin wrote:
Hi all,
We monitor JT, NN and SNN memory usage and observe the following
behavior in our Hadoop cluster. JT's heap size is set to 2000m.
About 18
hours a day it uses ~1GB but every day roughly at the minute it was
started its used memory increases to ~1.5GB and then decreases back
to
~1GB in about 6 hours. Sometimes this takes a bit more than 6 hours,
sometimes a bit less. I was wondering whether anyone here knows what
JT
does once a day that makes it use 1.5 times more memory than
normally.
We're so interested in JT memory usage because during last two weeks
we
twice had JT getting out of heap space. Both times right after those
daily used memory peaks when it was going down from 1.5GB to 1GB it
started increasing again until got stuck at ~2.2GB. After that it
becomes unresponsive and we have to restart it.
We're using Cloudera's CDH2 version 0.20.1+169.113.
--
Regards, Max
