Ask Your Question

Sahara: Change Java heap space

asked 2014-07-24 11:07:48 -0500

datts gravatar image

Hi everybody,

I have created a cluster hadoop (When create Node group template, I have modified "-Xmx200m" to "-Xmx1024m"). Then i ssh to master-instance and run: "hadoop jar hadoop-examples-1.2.1.jar pi 10 100", I get the error:

java.lang.OutOfMemoryError: Java heap space

Check file /etc/hadoop/ I see:


Then, I edit 128 to 1024:


When run "hadoop jar hadoop-examples-1.2.1.jar pi 10 100", it's worked! But, my cluster still in a state: "Watting" and ip_master:50030/jobtracker.jps not running?

Why HADOOP_CLIENT_OPTS in /etc/hadoop/ not automatic update when create cluster?

What is the problem here? Thank you very much!

edit retag flag offensive close merge delete

1 answer

Sort by ยป oldest newest most voted

answered 2014-08-08 13:12:12 -0500

alazarev gravatar image

First of all, which process failed with OutOfMemoryError? I would say that it is not likely something controlled by client opts.

Second, and HADOOP_CLIENT_OPTS control the same params, but in different ways. Overwriting of will lead to new value in mapred-site.xml and I believe you have right value because of "I have modified". This has nothing to do with file.

Third, Sahara doesn't expect you do any job executions until cluster is in Active state. Cluster in "Waiting" state means that Sahara didn't finish hadoop installation and cluster is not ready for job executions yet. You need to fix this issue first.

edit flag offensive delete link more


Hi alazarew,

This issue related to my questions at:

I'm still trying to fix this error :(

P/s: The time now, i'm installing OpenStack Icehouse on KVM virtual machine (Ubuntu12.04). I suspect the problem here. I will reinstall it on a physical server and report results.


datts gravatar imagedatts ( 2014-08-11 09:30:25 -0500 )edit

OpenStack works well on virtual machine. Virtualization may have impact on performance (nested virtualization helps a lot here), but in general there should be no difference.

alazarev gravatar imagealazarev ( 2014-08-11 15:49:34 -0500 )edit
datts gravatar imagedatts ( 2014-08-13 02:49:37 -0500 )edit

Get to know Ask OpenStack

Resources for moderators

Question Tools

1 follower


Asked: 2014-07-24 11:07:48 -0500

Seen: 1,056 times

Last updated: Jul 24 '14