I'm making a guesswork here. Are the namenode, datanode, jobtracker and testtracker separate java processes? Does each of them take up separate heap spaces? (Running Jps would show them separately - I guess they may be separate java processes with separate heap spaces). If that's true, then, if the total memory is X, and you are allocating Y as the heapspace, then 4*Y must be much less than X.
I'm not sure - this is what I'm speculating. Can anyone confirm this please? Cheers Arijit 2009/2/26 Nick Cen <cenyo...@gmail.com> > I got a question relatived to the HADOOP_HEAPSIZE variable. My machine's > memory size is 16G. but when i set HADOOP_HEAPSIZE to 4GB, it thrown the > exception refered in this thread. how can i make full use of my mem. thx. > > 2009/2/26 Arijit Mukherjee <ariji...@gmail.com> > > > I was getting similar errors too while running the mapreduce samples. I > > fiddled with the hadoop-env.sh (where the HEAPSIZE is specified) and the > > hadoop-site.xml files - and rectified it after some trial and error. But > I > > would like to know if there is a thumb rule for this. Right now, I've a > > core > > duo machine with 2GB RAM running on Ubuntu 8.10, and I've found that a > > HEAPSIZE of 256Mb works without any problems. Anything more than that > would > > give the same error (even when nothing else is going on in the machine). > > > > Arijit > > > > 2009/2/26 Anum Ali <miss.anum...@gmail.com> > > > > > If the solution given my Matei Zaharia wont work , which I guess it > > > wont if you are using eclipse 3.3.0 because this is a bug , which they > > > resloved it in later version which is eclipse 3.4 ganymede. Better > > > upgrade eclipse version. > > > > > > > > > > > > > > > On 2/26/09, Matei Zaharia <ma...@cloudera.com> wrote: > > > > These variables have to be at runtime through a config file, not at > > > compile > > > > time. You can set them in hadoop-env.sh: Uncomment the line with > export > > > > HADOOP_HEAPSIZE=<whatever> to set the heap size for all Hadoop > > processes, > > > or > > > > change options for specific commands. Now these commands are for the > > > Hadoop > > > > processes themselves, but if you are getting the error in tasks > you're > > > > running, you can set these in your hadoop-site.xml through the > > > > mapred.child.java.opts variable, as follows: > > > > <property> > > > > <name>mapred.child.java.opts</name> > > > > <value>-Xmx512m</value> > > > > </property> > > > > > > > > By the way I'm not sure if -J-Xmx is the right syntax; I've always > seen > > > -Xmx > > > > and -Xms. > > > > > > > > On Wed, Feb 25, 2009 at 5:05 PM, madhuri72 <akil...@gmail.com> > wrote: > > > > > > > >> > > > >> Hi, > > > >> > > > >> I'm trying to run hadoop version 19 on ubuntu with java build > > > >> 1.6.0_11-b03. > > > >> I'm getting the following error: > > > >> > > > >> Error occurred during initialization of VM > > > >> Could not reserve enough space for object heap > > > >> Could not create the Java virtual machine. > > > >> make: *** [run] Error 1 > > > >> > > > >> I searched the forums and found some advice on setting the VM's > memory > > > via > > > >> the javac options > > > >> > > > >> -J-Xmx512m or -J-Xms256m > > > >> > > > >> I have tried this with various sizes between 128 and 1024 MB. I am > > > adding > > > >> this tag when I compile the source. This isn't working for me, and > > > >> allocating 1 GB of memory is a lot for the machine I'm using. Is > > there > > > >> some > > > >> way to make this work with hadoop? Is there somewhere else I can > set > > > the > > > >> heap memory? > > > >> > > > >> Thanks. > > > >> > > > >> > > > >> > > > >> > > > >> > > > >> -- > > > >> View this message in context: > > > >> > > > > > > http://www.nabble.com/Could-not-reserve-enough-space-for-heap-in-JVM-tp22215608p22215608.html > > > >> Sent from the Hadoop core-user mailing list archive at Nabble.com. > > > >> > > > >> > > > > > > > > > > > > > > > -- > > "And when the night is cloudy, > > There is still a light that shines on me, > > Shine on until tomorrow, let it be." > > > > > > -- > http://daily.appspot.com/food/ > -- "And when the night is cloudy, There is still a light that shines on me, Shine on until tomorrow, let it be."
