There are 0 datanode(s) running and no node(s) are excluded in this operation

≡放荡痞女 提交于 2019-11-27 07:38:16

Two things worked for me,

STEP 1 : stop hadoop and clean temp files from hduser

sudo rm -R /tmp/*

also, you may need to delete and recreate /app/hadoop/tmp (mostly when I change hadoop version from 2.2.0 to 2.7.0)

sudo rm -r /app/hadoop/tmp
sudo mkdir -p /app/hadoop/tmp
sudo chown hduser:hadoop /app/hadoop/tmp
sudo chmod 750 /app/hadoop/tmp

STEP 2: format namenode

hdfs namenode -format

Now, I can see DataNode

hduser@prayagupd:~$ jps
19135 NameNode
20497 Jps
19477 DataNode
20447 NodeManager
19902 SecondaryNameNode
20106 ResourceManager

I had the same problem after improper shutdown of the node. Also checked in the UI the datanode is not listed.

Now it's working after deleting the files from datanode folder and restarting services.

stop-all.sh

rm -rf /usr/local/hadoop_store/hdfs/datanode/*

start-all.sh

@Learner,
I had this problem of datanodes not shown in the Namenode's web UI. Solved it by these steps in Hadoop 2.4.1.

do this for all the nodes (master and slaves)

1. remove all temporary files ( by default in /tmp) - sudo rm -R /tmp/*.
2. Now try connecting to all nodes through ssh by using ssh username@host and add keys in your master using ssh-copy-id -i ~/.ssh/id_rsa.pub username@host to give unrestricted access of slaves to the master (not doing so might be the problem for refusing connections).
3. Format the namenode using hadoop namenode -format and try restarting the daemons.

On my situation, firewalld service was running. It was on default configuration. And it don't allow the communication between nodes. My hadoop cluster was a test cluster. Because of this, I stopped the service. If your servers are in production, you should allow hadoop ports on firewalld, instead of

service firewalld stop
chkconfig firewalld off

I had same error. I had not permission to hdfs file system. So I give permission to my user:

chmod 777 /usr/local/hadoop_store/hdfs/namenode
chmod 777 /usr/local/hadoop_store/hdfs/datanode
smooth_smoothie

In my situation, I was missing the necessary properties inside hdfs-site.xml (Hadoop 3.0.0) installed using HomeBrew on MacOS. (The file:/// is not a typo.)

<property>
    <name>dfs.namenode.name.dir</name>
    <value>file:///usr/local/Cellar/hadoop/hdfs/namenode</value>
</property>

<property>
    <name>dfs.datanode.data.dir</name>
    <value>file:///usr/local/Cellar/hadoop/hdfs/datanode</value>
</property>

It is probably because the cluster ID of the datanodes and the namenodes or node manager do not match. The cluster ID can be seen in the VERSION file found in both the namenode and datanodes .

This happens when you format your namenode and then restart the cluster but the datanodes still try connecting using the previous clusterID . to be successfully connected you need the correct IP address and also a matching cluster ID on the nodes.

So try reformatting the namenode and datanodes or just configure the datanodes and namenode on newly created folders.

That should solve your problem.

Deleting the files from the current datanodes folder will also remove the old VERSION file and will request for a new VERSION file while reconnecting with the namenode.

Example you datanode directory in the configuration is /hadoop2/datanode

$ rm -rvf /hadoop2/datanode/*

And then restart services If you do reformat your namenode do it before this step. Each time you reformat your namenode it gets a new ID and that ID is randomly generated and will not match the old ID in your datanodes

So every time follow this sequence

if you Format namenode then Delete the contents of datanode directory OR configure datanode on newly created directory Then start your namenode and the datanodes

Value for property {fs.default.name} in core-site.xml, on both the master and slave machine, must point to master machine. So it will be something like this:

<property>
     <name>fs.default.name</name>
     <value>hdfs://master:9000</value>
</property>

where master is the hostname in /etc/hosts file pointing to the master node.

Have you tried clearing the /tmp folder.

Before cleanup a datanode did not come up

86528 SecondaryNameNode
87719 Jps
86198 NameNode
78968 RunJar
79515 RunJar
63964 RunNiFi
63981 NiFi

After cleanup

sudo rm -rf /tmp/*

It worked for me

89200 Jps
88859 DataNode

@mustafacanturk solution, disabling the firewall worked for me. I thought that datanodes started because they appeared up when running jps but when trying to upload files i was receiving the message "0 nodes running". In fact neither the web interface to (http://nn1:50070) was working because of the firewall. I disabled the firewall when installing hadoop but for some reason it was up. Neverthelsess sometimes cleaning or recreating the temp folders (hadoop.tmp.dir) or even dfs.data.dir and dfs.namenode.name.dir folders and reformating the name server was the solution.

I have face same issue in my single node cluster.

I have done below steps in order to resolve this issue:
1. Checked datanode log under logs directory and found that namenode clusterId and datanode clusterId are different.
2. Make empty datanode directory:
rm -rvf /hadoop/hdfs/datanode/*
3. stop-all.sh
4. hdfs namenode -format
5. start-all.sh
6. jps
27200 NodeManager
26129 NameNode
26595 SecondaryNameNode
5539 GradleDaemon
2355 Main
2693 GradleDaemon
27389 Jps
26846 ResourceManager
26334 DataNode

This works for me.

Maybe the service of firewall hasn't been stopped.

1) Stop all services first using command stop-all.sh

2) Delete all files inside datanode rm -rf /usr/local/hadoop_store/hdfs/datanode/*

3) Then start all services using command start-all.sh

You can check if all of your services are running using jps command

Hope this should work!!!

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