hadoop NullPointerException

master: at org.apache.hadoop.net.NetUtils.createSocketAddr(NetUtils.java:134)\nmaster: at org.apache.hadoop.hdfs.server.namenode.NameNode.getAddress(NameNode.java:156)\nmaster: at org.apache.hadoop.hdfs.server.namenode.NameNode.getAddress(NameNode.java:160)\n\n\nIt seems that your secondary namenode has trouble connecting to the primary namenode, which is definitely required for the whole system to rock the road, for there's checkpointing things need to be done. So I guess there's something wrong with your network configuration, including: \n\n\n${HADOOP_HOME}/conf/core-site.xml,which contains something like this:\n\n<!-- Put site-specific property overrides in this file. -->\n<configuration>\n <property>\n <name>hadoop.tmp.dir</name>\n <value>/app/hadoop/tmp</value>\n <description>A base for other temporary directories.</description>\n </property>\n\n <property>\n <name>fs.default.name</name>\n <value>hdfs://master:54310</value>\n <description>The name of the default file system. A URI whose\n scheme and authority determine the FileSystem implementation. The\n uri's scheme determines the config property (fs.SCHEME.impl) naming\n the FileSystem implementation class. The uri's authority is used to\n determine the host, port, etc. for a filesystem.</description>\n </property>\n</configuration>\n\nand the /etc/hosts. This file is really a slippy slope, you gotta be careful with these ip alias name, which should be consistent with the hostname of the machine with that ip.\n\n 127.0.0.1 localhost\n 127.0.1.1 zac\n\n # The following lines are desirable for IPv6 capable hosts\n ::1 ip6-localhost ip6-loopback\n fe00::0 ip6-localnet\n ff00::0 ip6-mcastprefix\n ff02::1 ip6-allnodes\n ff02::2 ip6-allrouters\n\n 192.168.1.153 master #pay attention to these two!!!\n 192.168.99.146 slave1\n\n",

Apparently the defaults are not correct so you have to add them yourself as described in this post\n\n\nhttp://amitava1.blogspot.in/2010/01/hadoop-0201-null-pointer-exception-on.html\n\n\nIt worked for me.",

It seems you have not installed hadoop in your datanode(slave) at all (or) you have done it in a wrong path. The correct path in your case should be /home/hadoop/project/hadoop-0.20.2/",

Your bash scripts seem not to have the execute rights or don't even exist:\n\n\n slave: bash: line 0: cd: /home/hadoop/project/hadoop-0.20.2/bin/..: No such file or directory\n slave: bash: /home/hadoop/project/hadoop-0.20.2/bin/hadoop-daemon.sh: No such file or directory\n",