I recently installed Hadoop 3.3.1 on Ubuntu (single node cluster) using this tutorial.
The start-dfs.sh and start-yarn.sh shows all the processing running properly.
However when I use the jps command, it returns only jps, with none of the other nodes, trackers showing.
I am new to Hadoop and lost on how to solve this. Any help is appreciated.
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I am trying to set of a multi-node hadoop cluster using Hadoop 3.0.0. There is no straightforward documentation on this so I had to read a lot of blogs. I am at a point where when I run start-all.sh I see daemon processes appearing in the name node as well as data nodes. However, when I go to http://namenode:9870 I see 0 live nodes.
To be more specific when I run start-all.sh I see
and I when I run jps I see NameNode, SecondaryNameNode and ResourceManager processes are running. On data nodes running jps shows DataNode and NodeManager are running.
What I get on the url is
Any guidance is greatly appreciated.
Thanks
I have a confusion with hadoop 2.7.
After I run the start-all.sh, I type the jps command, but I haven't find jobtracker and tasktracker in the list, why?
Thanks for any help!
In Hadoop-2.7.2, mapreduce framework changed to YARN. So you can find Resourcemanager and Nodemanager instead of jobtracker and tasktracker.
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unable to see Task tracker and Jobtracker after Hadoop single node installation 2.5.1
For technical information, check the below link
http://blog.cloudera.com/blog/2013/11/migrating-to-mapreduce-2-on-yarn-for-operators/
Iam new to Hadoop 2.5.1. As i have already installed Hadoop 1.0.4 previously, i thought installation process would be same so followed following tutorial.
http://www.michael-noll.com/tutorials/running-hadoop-on-ubuntu-linux-single-node-cluster/
Every thing was fine, even i have given these settings in core-site.xml
<name>fs.default.name</name>
<value>hdfs://localhost:54310</value>
But i have seen in several sites this value as 9000.
And also changes in yarn.xml.
Still everything works fine when i run a mapreduce job. But my question is
when i run command jps it gives me this output..
hduser#secondmaster:~$ jps
5178 ResourceManager
5038 SecondaryNameNode
4863 DataNode
5301 NodeManager
4719 NameNode
6683 Jps
I dont see task tracker and job tracker in jps. Where are these demons running.
And without these deamons how am i able to run Mapreduce job.
Thanks,
Sreelatha K.
From hadoop version hadoop 2.0 onwards, default processing framework has been changed to YARN from Classic Mapreduce. You are using YARN, where you cannot see Jobtracker, Tasker in YARN. Jobtracker and Tasktracker is replaced by Resource manager and Nodemanager respectively in YARN.
But still you have an option to use Classic Mapreduce framework instead of YARN.
In Hadoop 2 there is an alternative method to run MapReduce jobs, called YARN. Since you have made changes in yarn.xml, MapReduce processing happens using YARN, not using the traditional MapReduce framework. That's probably be the reason why you don't see TaskTracker and JobTracker listed after executing the jps command. Note that ResourceManager and NodeManager are the daemons for YARN.
YARN is next generation of Resource Manager who can able to integrate with Apache spark, storm and many more tools you can use to write map-reduce jobs
I am running CDH5 on Ubuntu. I have installed everything i need, but when i type in sudo jps, the jobtracker is not displayed. Heres my configuration on mapred-site.xml
mapred.job.tracker.http.address: localhost{50030|50020}
Can someone please explain why this is happening? How can it be fixed?
what is your hadoop version? If it is 0.20.2+ then there is no need of configuring the jobtracker as they have removed the seperate jobtracker functionality. You can find it at localhost:8088.
Remove the configuration and restart the node
If it is an older version then try to manually start it using:
$hadoop jobtracker
if it doe not start, post the error log here
I would like to see if the hdfs file system for Hadoop is working properly. I know that jps lists the daemons that are running, but I don't actually know which daemons to look for.
I ran the following commands:
$HADOOP_PREFIX/sbin/hadoop-daemon.sh start namenode
$HADOOP_PREFIX/sbin/hadoop-daemon.sh start datanode
$HADOOP_PREFIX/sbin/yarn-daemon.sh start resourcemanager
$HADOOP_PREFIX/sbin/yarn-daemon.sh start nodemanager
Only namenode, resourcemanager, and nodemanager appeared when I entered jps.
Which daemons are supposed to be running in order for hdfs/Hadoop to function? Also, what could you do to fix hdfs if it is not running?
Use any of the following approaches for to check your deamons status
JPS command would list all active deamons
the below is the most appropriate
hadoop dfsadmin -report
This would list down details of datanodes which is basically in a sense your HDFS
cat any file available in hdfs path.
So, I spent two weeks validating my setup (it was fine) , finally found this command:
sudo -u hdfs jps
Initially my simple JPS command was showing only one process, but Hadoop 2.6 under Ubuntu LTS 14.04 was up. I was using 'Sudo' to run the startup scripts.
Here is the startup that work with JPS listing multiple processes:
sudo su hduser
/usr/local/hadoop/sbin/start-dfs.sh
/usr/local/hadoop/sbin/start-yarn.sh