Jameson, The right process to add a new node with the right mapping is:
1. Update topology file for the new DN. 2. Issue a dfsadmin -refreshNodes to get new topology mapping updated in NN. 3. Start the DN only after (2) so it picks up the right mapping and a default mapping does not get cached. On Thu, Sep 13, 2012 at 8:33 AM, Jameson Li <[email protected]> wrote: > Our hadoop version is hadoop-0.20-append+4. > > We have configured the rack awareness in the namenode. > But when I add new datanode, and update the topology data file, and restart > the datanode, I just see the log in the namenode that: > 2012-09-13 10:35:25,074 INFO org.apache.hadoop.net.NetworkTopology: Adding a > new node: /default-rack/ipc:50010 > So should I restart the namenode? > Is there some command like 'hadoop dfsadmin -refreshtopology'? > > My configuration: > > core-site.xml: > <property> > <name>topology.script.file.name</name> > <value>conf/rack-awareness.sh</value> > </property> > <property> > <name>topology.script.number.args</name> > <value>1000</value> > </property> > > conf/rack-awareness.sh: > #!/bin/sh > > HADOOP_CONF=/opt/hadoop/conf > > while [ $# -gt 0 ] ; do > nodeArg=$1 > exec< ${HADOOP_CONF}/topology.data > result="" > while read line ; do > ar=( $line ) > if [ "${ar[0]}" = "$nodeArg" ] ; then > result="${ar[1]}" > fi > done > shift > if [ -z "$result" ] ; then > echo -n "/default-rack " > else > echo -n "$result " > fi > done > > topology.data： > ipa rackA > ipb rackA > ipc rackB > > > And also I have search the mailing list "topology.script.file update": > I found a mail that: > Tom Hall 2011-10-27, 16:07 > I was hoping that if I updated the file it would give new answers as > datanodes were restarted and reconnected but that does not seem to be > the case. > Surely I dont need to restart the namenode... > > But there is not replying. > So somebody can help me? > > > 专注于Mysql,MSSQL,Oracle,Hadoop -- Harsh J
