I am rather new to hadoop, but wouldnt the difference be potentially in how the files are split in terms of size?
--- Regards, Jonathan Aquilina Founder Eagle Eye T On 2015-02-21 21:54, Fang Zhou wrote: > Hi All, > > I want to test the memory usage on Namenode and Datanode. > > I try to use jmap, jstat, proc/pid/stat, top, ps aux, and Hadoop website > interface to check the memory. > The values I get from them are different. I also found that the memory always > changes periodically. > This is the first thing confused me. > > I thought the more files stored in Namenode, the more memory usage in > Namenode and Datanode. > I also thought the memory used in Namenode should be larger than the memory > used in each Datanode. > However, some results show my ideas are wrong. > For example, I test the memory usage of Namenode with 6000 and 1000 files. > The "6000" memory is less than "1000" memory from jmap's results. > I also found that the memory usage in Datanode is larger than the memory used > in Namenode. > > I really don't know how to get the memory usage in Namenode and Datanode. > > Can anyone give me some advices? > > Thanks, > Tim
