I installed Hadoop-3.3.4 in Ubuntu-20. I wrote the command for starting hadoop, i.e.

samar@pc:~$ $HADOOP_HOME/sbin/start-all.sh Then it showed the output as.

WARNING: Attempting to start all Apache Hadoop daemons as samar in 10 seconds.
WARNING: This is not a recommended production deployment configuration.
WARNING: Use CTRL-C to abort.
Starting namenodes on [localhost]
Starting datanodes
Starting secondary namenodes [pc]
Starting resourcemanager
Starting nodemanagers

But when I tried to access the HDFS with the command

samar@pc:~$ hdfs dfs -ls It gave a message as:

ls: Call From pc/127.0.1.1 to localhost:9000 failed on connection exception: 
java.net.ConnectException: Connection refused; For more details see:  
http://wiki.apache.org/hadoop/ConnectionRefused

and the output of jps was:

10485 Jps
10101 NodeManager
9946 ResourceManager
9739 SecondaryNameNode
9533 DataNode

CodePudding user response：

Namenode did not start successfully (9000 is namenodes services port)

Are there more logs?