In a further test, I tried connecting to the NameNode from hadoop-master (where it's running) using both the hostname and the IP address.
vagrant@hadoop-master:~/src$ telnet 192.168.51.4 54310 Trying 192.168.51.4... telnet: Unable to connect to remote host: Connection refused vagrant@hadoop-master:~/src$ telnet localhost 54310 Trying 127.0.0.1... telnet: Unable to connect to remote host: Connection refused vagrant@hadoop-master:~/src$ telnet hadoop-master 54310 Trying 127.0.1.1... Connected to hadoop-master. Escape character is '^]'. As you can see the IP address or localhost connection is refused, but the hostname connection succeeds. Is there some way to configure the namenode to accept connections from all hosts? On Thu, Sep 24, 2015 at 2:14 PM, Daniel Watrous <[email protected]> wrote: > On one of the namenodes I have found the following warning: > > 2015-09-24 18:40:17,639 WARN > org.apache.hadoop.hdfs.server.datanode.DataNode: Problem connecting to > server: hadoop-master/192.168.51.4:54310 > > On my master node I see that the process is running and has bound that port > > vagrant@hadoop-master:~/src$ sudo lsof -i :54310 > COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME > java 7480 hadoop 202u IPv4 26931 0t0 TCP hadoop-master:54310 > (LISTEN) > java 7480 hadoop 212u IPv4 28758 0t0 TCP > hadoop-master:54310->localhost:47226 (ESTABLISHED) > java 7651 hadoop 238u IPv4 28247 0t0 TCP > localhost:47226->hadoop-master:54310 (ESTABLISHED) > hadoop@hadoop-master:~$ jps > 7856 SecondaryNameNode > 7651 DataNode > 7480 NameNode > 8106 Jps > > I don't appear to have any firewall rules interfering with traffic > vagrant@hadoop-master:~/src$ sudo iptables --list > Chain INPUT (policy ACCEPT) > target prot opt source destination > > Chain FORWARD (policy ACCEPT) > target prot opt source destination > > Chain OUTPUT (policy ACCEPT) > target prot opt source destination > > The iptables --list output is identical on hadoop-data1. I also show a > process attempting to connect to hadoop-master > vagrant@hadoop-data1:~$ sudo lsof -i :54310 > COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME > java 3823 hadoop 238u IPv4 19304 0t0 TCP > hadoop-data1:45600->hadoop-master:54310 (SYN_SENT) > > I am confused by the notation of hostname/IP:port. > All help appreciated. > > Daniel > > > > On Thu, Sep 24, 2015 at 12:51 PM, Daniel Watrous <[email protected]> > wrote: > >> I have a multi-node cluster with two datanodes. After running >> start-dfs.sh, I show the following processes running >> >> hadoop@hadoop-master:~$ $HADOOP_HOME/sbin/slaves.sh jps >> hadoop-master: 10933 DataNode >> hadoop-master: 10759 NameNode >> hadoop-master: 11145 SecondaryNameNode >> hadoop-master: 11567 Jps >> hadoop-data1: 5186 Jps >> hadoop-data1: 5059 DataNode >> hadoop-data2: 5180 Jps >> hadoop-data2: 5053 DataNode >> >> >> However, the other two DataNodes aren't visible. >> http://screencast.com/t/icsLnXXDk >> >> Where can I look for clues? >> > >
