Thanks Brahma, I am kind of afraid to run the command, I had an issue on jobtracker early this year. I launched the command and it caused the jobtracker stop responding long enough till we need to roll the jobtracker instead. So i am kind of afraid to run it on the production namenode. Any suggestion is more than welcome.
On Mon, Jun 17, 2013 at 6:45 PM, Brahma Reddy Battula < [email protected]> wrote: > Can you take heapdump and check ..? Here you can check which objects are > using how much.. > > > > Command : *jmap -histo:live namenodepid* > ------------------------------ > *From:* Personal [[email protected]] > *Sent:* Tuesday, June 18, 2013 7:20 AM > *To:* [email protected] > *Subject:* Re: Namenode memory usage > > > E Lego > > > On Mon, Jun 17, 2013 at 1:04 PM, Patai Sangbutsarakum < > [email protected]> wrote: > >> Hi Hadoopers, >> >> My dedicated Namenode box has 48G of memory, 40G is allocated for NN. >> HEAP >> >> This is from 50070/dfshealth.jsp >> *28540193 files and directories, 32324098 blocks = 60864291 total. Heap >> Size is 23.34 GB / 38.54 GB (60%) * >> >> *The Heap is fluctuating between less than 20G up to almost 100%* >> * >> * >> * >> * >> However, from top command Residence size is constantly at 39G not matter >> how low of the memory usage in defshealth.jsp page >> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND >> >> 4628 apps 19 0 40.4g 39g 22m S 132.9 83.9 44821:08 >> /usr/java/jdk/jre/bin/java -Dproc_namenode -Xmx40000m >> >> >> Is this the time to upgrade the ram to the namenode box? >> >> I remember the easy rule of thumb is 150 bye of every 1M for >> blocks+file+dir, so *60864291 * 150byte is around 9G. I just don't >> understand why 40G seems to be used up.?* >> *Please educate..* >> * >> * >> *Hope this make sense* >> *P* >> > >
