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From Harsh J <ha...@cloudera.com>
Subject Re: Used Heap in Namenode & dfs.replication
Date Fri, 12 Oct 2012 16:03:12 GMT
Apache Hadoop 0.20.2 may not have accurate heap usage report on that
web UI. See https://issues.apache.org/jira/browse/HDFS-94 for the fix
we had to do. You may measure actual usage via either jmap -histo:live
or via http://NNWebUI:PORT/jmx if thats available (shows some JVM
metrics you can consume).

On Fri, Oct 12, 2012 at 12:03 AM, Patai Sangbutsarakum
<silvianhadoop@gmail.com> wrote:
> Hi Hadoopers,
>
> I am looking at DFS' cluster summary.
>
> "14708427 files and directories, 16357951 blocks = 31066378 total"
>
> From White's book (2nd Edition) page 42. "As a rule of thumb, each
> file, directory, and block takes about 150bytes".
>
> So, 31066378 * 150 byte => 4.34 GB
>
> The rest of the line is  Heap Size is 12.17 GB / 34.72 GB
>
> 12.17 vs. 4.34 is like 3 time bigger number. is that because of
> replication of 3 ?
>
> Thanks
> Patai
>
> I am on 0.20.2



-- 
Harsh J

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