Hi Charles, In my hadoop-env.sh, I set
export HADOOP_CLIENT_OPTS="-Dhadoop.root.logger=DEBUG,console -Xmx512m $HADOOP_CLIENT_OPTS" However, I could not see the debug log in NN's log file hadoop-xilan-namenode-xxxx.out. By setting export HADOOP_ROOT_LOGGER="DEBUG,console" I could see lots of debug log. One more question is what will be written to the .log file and what will be written to the .out file ? @Rich, I also tried your method but I could not see the debug log as well. I must be missing something. Thanks, Xiaohe On Tue, Mar 24, 2015 at 10:55 PM, Rich Haase <rha...@pandora.com> wrote: > If you want to enable debug logging of all hadoop components you can add > this line to your log4j.properties. > > log4j.logger.org.apache.hadoop=DEBUG > > However, in a 3 node cluster that is doing next to nothing this produces a > lot of log output, so I find it preferable to specify an one daemon type at > a time to enable debug logging on, e.g. > > log4j.logger.org.apache.hadoop.NameNode=DEBUG > > It’s also worth while to review the hadoop daemonlog command, which can be > used to change the log level of running daemons. > > Cheers, > > Rich > > On Mar 24, 2015, at 10:38 AM, Charles Lamb <cl...@cloudera.com<mailto: > cl...@cloudera.com>> wrote: > > One way is to do: > > HADOOP_CLIENT_OPTS="-Dhadoop.root.logger=DEBUG,console" > > IHTH. > > Charles > > On 3/24/2015 10:25 AM, xiaohe lan wrote: > ---------- Forwarded message ---------- > From: xiaohe lan <zombiexco...@gmail.com<mailto:zombiexco...@gmail.com>> > Date: Tue, Mar 24, 2015 at 9:04 PM > Subject: How to enable debug log in HDFS > To: u...@hadoop.apache.org<mailto:u...@hadoop.apache.org> > > > Hi expert, > > I am using Hadoop 2.4, I need to see the debug log of HDFS when performing > some operations. Where can I set it. I did a search in log4j.properties but > I don't what can I do with it. > > Thanks, > Xiaohe > > > >