I Installed Hadoop 2.4.X. As expected there is no JobTracker and TaskTracker. Its Yarn based. Is there any way to make it use old JobTracker and TaskTracker for MapReduce and not based on Yarn ? In short can I make JT and TT daemons running on this ?
By default there is no configuration file for map reduce in the 2.4.x installation even though there is a file called mapred-site.xml.template.Rename the file to mapred-site.xml and remember to set the property mapred.framework.name to classic to use the job tracker and tasktracker.Also the start scripts start-all.sh cannot be used as it executes the scripts start-dfs.sh and start-yarn.sh.You need to execute the script that starts jobtracker and tasktracker.
As described above, there is no Jobtracker and Tasktracer in Hadoop 2.0 (yarn). It's better to follow this instruction (http://codesfusion.blogspot.in/2013/10/setup-hadoop-2x-220-on-ubuntu.html) to get the idea, and you will find the processes are as:
25578 ResourceManager
25411 SecondaryNameNode
447 Jps
29464 NameNode
25222 DataNode
25905 NodeManager
Related
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.
Similar Questions
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/
Job tracker and Task tracker don't sow up when ran the start-all.sh command in ububtu for hadoop
I do get the rest of the processes while i run the "JPS" command in unix.
Not sure why i am not being shown with the job tracker and task tracker.Have been following couple of links and couldn't get my prob sorted.
Steps done :
-Multiple times formatted the namenode
-Multiple time deleted and recreated the tmp folder with appropriate permissions.
What could be the issue ?
Any suggestions would really help me as i am struggling in setting up hadoop on my laptop.I am new to it though.
Try starting jobtracker and tasktracker separately.
From your hadoop HOME directory run
. bin/../libexec/hadoop-config.sh
Then from hadoop BIN directory run
hadoop-daemon.sh --config $HADOOP_CONF_DIR start jobtracker
hadoop-daemon.sh --config $HADOOP_CONF_DIR start tasktracker
You must have been using hadoop 2.x version where jobtracker is replaced with YARN resource manager. Using jps(jdk is needed) you can check whether resouce manager is running. If it is running then the default url for it is (host-name):8088. You can check your nodes,jobs also configuration there.If not running then start them with sbin/start-yarn.sh.
What I know is YARN is introduced and it replaced JobTracker and TaskTracker.
I have seen is some Hadoop 2.6.0/2.7.0 installation tutorials and they are configuring mapreduce.framework.name as yarn and mapred.job.tracker property as local or host:port.
The description for mapred.job.tracker property is
"The host and port that the MapReduce job tracker runs at. If "local",
then jobs are run in-process as a single map and reduce task."
My doubt is why are configuring it if we are using YARN , I mean JobTracker shouldn't be running right?
Forgive me if my question is dumb.
Edit: These are the tutorials I was talking about.
http://chaalpritam.blogspot.in/2015/01/hadoop-260-multi-node-cluster-setup-on.html
http://pingax.com/install-apache-hadoop-ubuntu-cluster-setup/
https://chawlasumit.wordpress.com/2015/03/09/install-a-multi-node-hadoop-cluster-on-ubuntu-14-04/
This is just a guess, but either those tutorials talking about configuring the JobTracker in YARN are written by people who don't know what YARN is, or they set it in case you decide to stop working with YARN someday. You are right: the JobTracker and TaskTracker do not exist in YARN. You can add the properties if you want, but they will be ignored. New properties for each of the components replacing the JobTracker and the TaskTracker were added with YARN, such as yarn.resourcemanager.address to replace mapred.jobtracker.address.
If you list your Java processes when running Hadoop under YARN, you see no JobTrackeror TaskTracker:
10561 Jps
20605 NameNode
17176 DataNode
18521 ResourceManager
19625 NodeManager
18424 JobHistoryServer
You can read more about how YARN works here.
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 have started configuring Hadoop 2.1.0-beta version for single node. I followed steps mentioned in Michael Noll's Tutorial (http://www.michael-noll.com/tutorials/running-hadoop-on-ubuntu-linux-multi-node-cluster/#configuring-single-node-clusters-first). Every thing I did and configured well. As a result of JPS, I got that NameNode, DataNode, Secondary NameNode started fine. Then I found out that there is no start-mapred.sh script. So I tried starting the jobtracker using hadoop-daemons.sh (hadoop-daemon.sh --config /home/nayan/dev/hadoop/etc/hadoop/ start jobtracker) and it resulted in failure with message "Sorry, the jobtracker command is no longer supported. You may find similar functionality with the "yarn" shell command.". I do not know what all configuration changes (if any) I need to make. I made changes in "yarn-site.xml" file, as suggested in Hadoop:The Definitive Guide. But could not proceed further. Where can I find out about Yarn. I checked Apache site, but could not figure it out.
You need to check your configuration xml files. Sometimes if you have any problrm in xml then some daemons wont start.
and try to use ./start-all.sh and then JPS
you can use start-yarn.sh to start the ResourceManger and Jobtracker daemons
I usually start everything using these two commands
./start-dfs.sh
./start-yarn.sh
You Should use start-dfs.sh for Hdfs Daemons and start-yarn.sh for Resource manager and nodemanager daemon both are in /bin of hadoop.
./start-dfs.sh or start-dfs.sh will start only HDFS components , while ./start-yarn.sh or start-yarn.sh will start Yarn component like NodeManager , Resource manager etc. If you don't want to start both the components separately , try using this command :
./start-all.sh or start-all.sh (This is deprecated command though).
To answer your question , use ./start-yarn.sh
Cheers!
First have to start the yarn daemons in the YARN( HADOOP 2.x) Environment.
So start with this
at /hadoop_installed_path/sbin$ ./start-yarn.sh
Once the yarn daemons started then we can start df daemons
at /hadoop_installed_path/sbin$ ./start-dfs.sh
1.You should check all the steps in Hadoop The definitive guide.
if it's all proper than use start-all.sh
than run jps.
2.some time You have to close console for reflecting your changes.so close the console and reopen it again and then try jps,
hope this will help.