Skip to content

Hadoop

Jump to bottom
Dénes Harmath edited this page May 14, 2015 · 6 revisions

Tutorials

Troubleshooting

"Could only be replicated to 0 nodes" exception

A common exception is the following:

could only be replicated to 0 nodes, instead of ...

The documentation, http://wiki.apache.org/hadoop/CouldOnlyBeReplicatedTo says:

This is not a problem in Hadoop, it is a problem in your cluster that you are going to have to fix on your own. Sorry.

It's possible that the logs generated at the initialization contain this exception, but Hadoop/HDFS will work fine. The super hard reset of Hadoop looks like the following:

/usr/local/hadoop/bin/stop-all.sh
# delete the content of the HDFS directory on all nodes, the `4s-ssh-all` script comes with 4store
4s-ssh-all "rm -rf $hadoop_dir/tmp/*"
/usr/local/hadoop/bin/hadoop namenode -format -force
/usr/local/hadoop/bin/start-all.sh

wait,

/usr/local/hadoop/bin/hadoop dfs -copyFromLocal local-filename hdfs-filename
/usr/local/hadoop/bin/hadoop dfs -ls

YARN

Clone this wiki locally