Are you trying to implement something like namespace federation, that's a part of Hadoop 2.0 - http://hadoop.apache.org/docs/r2.0.3-alpha/hadoop-project-dist/hadoop-hdfs/Federation.html
On Thu, Apr 18, 2013 at 10:02 PM, Lixiang Ao <aolixi...@gmail.com> wrote: > Actually I'm trying to do something like combining multiple namenodes so > that they present themselves to clients as a single namespace, implementing > basic namenode functionalities. > > 在 2013年4月18日星期四，Chris Embree 写道： > > Glad you got this working... can you explain your use case a little? I'm >> trying to understand why you might want to do that. >> >> >> On Thu, Apr 18, 2013 at 11:29 AM, Lixiang Ao <aolixi...@gmail.com> wrote: >> >>> I modified sbin/hadoop-daemon.sh, where HADOOP_PID_DIR is set. It works! >>> Everything looks fine now. >>> >>> Seems direct command "hdfs namenode" gives a better sense of control :) >>> >>> Thanks a lot. >>> >>> 在 2013年4月18日星期四，Harsh J 写道： >>> >>> Yes you can but if you want the scripts to work, you should have them >>>> use a different PID directory (I think its called HADOOP_PID_DIR) >>>> every time you invoke them. >>>> >>>> I instead prefer to start the daemons up via their direct command such >>>> as "hdfs namenode" and so and move them to the background, with a >>>> redirect for logging. >>>> >>>> On Thu, Apr 18, 2013 at 2:34 PM, Lixiang Ao <aolixi...@gmail.com> >>>> wrote: >>>> > Hi all, >>>> > >>>> > Can I run mutiple HDFS instances, that is, n seperate namenodes and n >>>> > datanodes, on a single machine? >>>> > >>>> > I've modified core-site.xml and hdfs-site.xml to avoid port and file >>>> > conflicting between HDFSes, but when I started the second HDFS, I got >>>> the >>>> > errors: >>>> > >>>> > Starting namenodes on [localhost] >>>> > localhost: namenode running as process 20544. Stop it first. >>>> > localhost: datanode running as process 20786. Stop it first. >>>> > Starting secondary namenodes [0.0.0.0] >>>> > 0.0.0.0: secondarynamenode running as process 21074. Stop it first. >>>> > >>>> > Is there a way to solve this? >>>> > Thank you in advance, >>>> > >>>> > Lixiang Ao >>>> >>>> >>>> >>>> -- >>>> Harsh J >>>> >>> >>
