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I am logged in (via SSH) to the NameNode of my Hadoop cluster; the problem I am having is that any hadoop fs commands, even simple ones like hadoop fs -ls are completed quickly, but take many minutes to return control of the shell to the user. For instance, hadoop fs -ls prints the directory listing immediately, but the next bash prompt does not appear for nearly ten minutes. If I type hadoop fs -mkdir there is no output, but if I then open a new SSH session and type hadoop fs -ls I will see the directory in the path (of course, I will not be able to use either shell for a while after that).

I am running vanilla Hadoop on CentOS 6.2; I have eight nodes. If you need further information, please ask.


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Look at the namenode log. A more low-level approach would be to run strace hadoop fs -ls. – Mark Wagner Jul 7 '12 at 1:38

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